Note: This story was dynamically reformatted for online reading convenience. It all started when I was 12 years old, I heard noises coming from my parents room and I figured it was my mom and dad, but then I remembered that my mom was out that night, it couldn't be her, they rarely had sex, but the walls were thin and I could clearly hear them panting and saying sexual things to each other, when I was younger I had no idea what they meant, but I asked my twin sister one day, she was 2 hours older than me, I asked her what "fuck me" meant, and she explained it to me, I'd told her I heard the noises from my parents room and she said I should keep it to myself as it was private. I asked her if she had ever done anything sexual but she got embarrassed and told me to shut up, so I did... Until that night, I didn't want to see what was happening at the time, but I wanted to know who it was in my father's room, I left my own room quietly and quickly walked to my sisters room, the 3 of them shared, my 2 younger sisters Rachel and Zoe were asleep, but my twin sister Natasha was missing from her bed, again I didn't make the connection till I heard my parents' bedroom door open and whispers in the hall way, I froze and panicked, I didn't want to get caught in the girls room, so I dropped to the floor and rolled under Zoe's bed, I tried not to breath too loud as the room door opened and in walked Tash, she was crying quietly, my father was behind her and he was telling her to be quiet and go straight to sleep, my sisters nighty was short and her underwear looked wet, she sobbed as he tucked her in and left, I waited hours for my sister to go quiet before rolling out and going back to my own bedroom very confused. After that night I looked out for my father and Tasha coming together, she avoided him around the house and rarely spoke to him at all, mum took it as Tash being a moody 12 year old and didn't say anything to her about it, but when my mum went out for the night every Monday with her friends, I could hear Tash sobbing and my father making the noises, after a few months I put it together, he was sexually abusing her, how I didn't know, but it was clear that she spent time in his room at night and came out usually crying, I didn't really know what to do, or what to say, I almost told my mother one night but I didn't want to be the one to break my family apart, I didn't know what would happen if my parents got divorced, so I kept quiet, for a while... One summers morning I ended up being in the house with Tash, my parents allowed us to babysit the younger girls when we turned 13, so on that Saturday morning, around a week after our 13th Birthday, I faked feeling sick so they would leave me at home, Tash had already said she didn't want to go shopping so it was settled, I decided to ask her about what I knew. "Why don't you tell mum about what Dad does to you on Monday nights?" I said She immediately broke down and I sat with her on the sofa as she cried, eventually she talked. "It's not worth it, not worth them splitting up, it doesn't even really hurt anymore." She said "But you are not meant to do that stuff with kids, he might get sent to jail" I said "We can't afford to lose him, he's not always a bad man, I know he loves us, he just needs....... Someone, sometimes" She said "What does that mean?" "Look, I don't want to talk about this..... so please stop asking me, just don't say anything, to anyone... Just leave it" she said, I didn't press her, she had begun to get angry and I didn't want to make her any more upset. "I won't say anything, I promise" I said "Thanks Ollie" she said back and she hugged me real tight. Every Monday night my little sisters would get sent to bed at 7, myself and Tash would follow around an hour later but she would wait about 10 minutes and then go to my parents room, then around 20 minutes later I would hear my dad's feet on the stairs, he would go to his room and then sometimes I could hear them talking, I could never make anything out but I would hear them, then the rocking would start, a gentle squeak, in time, like a heartbeat, it would get louder for around half an hour then I could hear Dad talking again as the squeak got fast and loud towards the end, and then Tash sobbing, then eventually quiet, usually that would be it, but sometimes it started again after a half an hour break. The next time I got Tash alone was walking home from School one day, I asked her again and she told me to shut up, but I pressed her this time. "If it doesn't hurt then why do you always cry?" I said "It hurts at the end sometimes, when he go's faster, and it kind of makes me sad too" "What do you mean faster?" I asked "I told you to leave it alone, stop asking me about it, just keep quiet and don't mention it to anyone ever again, don't ask me and don't keep listening every week, just forget all about it" she said That was obviously impossible, I couldn't forget it, I couldn't concentrate on Mondays, because I knew what would happen after my dad kissed my mum as she left for Bingo, the noise, the squeaking, the sobbing, I got more and more curious and I had to find a way of listening better, so I could hear what my dad was saying.... I came up with a plan when I was playing my my dads phone, his Mobile, I found a sound recorder, it was set to 5 minutes only, but I took the limit off it and then I tested it, I played in my room with Zoe one day for well over 2 hours and when I checked it was still recording, I listened that night and the quality was good enough to hear us, even though I had left it under my bed. My dad didn't use his phone much and always switched it off when he was at home so he never missed it, that Monday I was very excited, I felt like I was a detective, I waited till my Mom left and when the clock got to 7:30 I asked if I could go to bed as I was tired, my dad said yes and sent the younger girls up too, they hated me at that moment but they would get over it, I went to my room and grabbed the phone I stashed, then after 10 minutes I crept quietly to my dad's room, I looked around for somewhere but the bed was solid and there was nothing to hide it under, Eventually I saw my mom's dressing gown, as it was summer she didn't wear it, it was just hanging there on a hook near the bed, I set the recorder and dropped it in the pocket and left, the night went exactly as routine, I heard Tash go in to my parents room and my Dad follow soon after, the rocking of the bed, the squeak of the Mattress, I checked my digitial clock and the squeak went on for about 45 minutes, then I heard my dad's voice and my sisters Sobbing, I fell asleep late that night, thinking about risking going in to my parents room to get the phone, I wanted to listen so much, but I must have fallen asleep thinking about it, I woke up at normal time and tried to get a chance to go into my parents room but someone was always in there, my Dad went crazy that morning because he couldn't find his phone to take to work, he ended up taking my mom's mobile with him, School went by so slow, I raced home and straight to the pocket, the phone was dead, I rooted around till I found my dads charger and plugged it in, it seemed to take forever to charge enough to turn the phone on, eventually it switched on and I hid under my covers, plugged my headphones in to the side and found the sound file, 3 hours and 12 minutes till the battery died and stopped the recording, I listened and caught the sound of myself climbing down off the bed and closing the door, then quiet for 20 minutes, I was going to try and forward it but I didn't know how, so I listened to the silence with incredible anticipation, I heard the door open and close, then the unfastening of a belt, the zip of some jeans, my sister undressing. I had never looked at any of my sisters sexually before that moment, I had been getting erections for months but never understood when and why they came, until then.... That moment I pictured my sister undressing and my cock hardened, I waited for another 10 minutes or so and then the door opened again, and closed. My father entered, then I heard him speak, clear as if I were standing right next to him. `Close your eyes and stand still'... Then silence for a few seconds... "Ok, now get on your knees on the bed, face away from me" My cock was so hard, I grabbed it and squeezed it, it felt good, then I heard the squeaking of the bed, loud squeaking, and a slighty wet sounding friction, squelching sound, and then heavy breathing coming from both Tash and my father, this went on for half an hour, then he spoke again. "Ok, now stand next to the bed and bend over again" he said. Then my sisters voice "not too hard, please.... It hurts" she said "I promised last week that I wouldn't go as hard on you this week, as long as you swallow it" "Ok" a weak reply from Tash, then I heard the slapping of skin against skin, legs impacting together, for the next 10 minutes, getting faster, till my dad started talking again "Oh hear it comes baby, get ready, on your knees.... Yeah..... Oh god this is so good.... Ooooh.... Ooooooooaaaahhh...." Followed by a coughing, choking, gurgling sound and then sobbing, from my sister. "You need to get over this Tash, we've been doing this for over a year, stop crying... calm down right now and stop that babyish crying, you are a woman now, not a kid" he said "Sorry dad.... Can I go now?" she said "No, you can wait tonight, your mum is going out to eat tonight so I've got you for another hour at least" I heard sobbing again, and my father telling Tash to stop.... I was stroking my cock as I listened. After around 30 minutes of shuffling and moving around, I heard him again. "Ok, take it in your mouth again and get me nice and hard." He said, no sobbing this time, squelching and sucking noises, I knew what she was doing to my dad and I felt my cock get so tingly, I stroked myself harder and harder, then when I heard the squeaking of the bed again I had my first orgasm, the first of 3 over the next 20 minutes of listening to my dad having sex with my sister. I tried and tried to think of some way I could save the voice recording on to something else but I wasn't smart enough then, I had no choice but to delete the file and then stash the phone under a seat cover at the dinner table, from that day on, I knew what they were doing on Monday nights, I heard the noises and knew exactly what was happening, after 2 more months, I was masturbating every night, but Mondays were best, with my noise show just through the wall, the next change was at the start of the cold weather, as the winter approached my mom moved my bed from the window wall to the opposite wall, to keep me warmer, she switched the room around and moved my wardrobe across the room, behind where it used to sit, on the wall between my parents room and my room was a vent, It was clearly an outer wall vent that had never been removed after the extension was built containing my room, it was around 3 feet from the floor and it was 8 by 10 inches in size, I noticed it and I thought about listening on Mondays, it made me excited, I masturbated that night thinking about Monday, and it was exactly as I hoped, I could hear them almost as good as the recording, not quite as good but almost. I was fooling around upstairs one weekend with my sisters playing hide and seek, even Tash was playing with us, I decided to hide inside my parents wardrobe, it was placed on the wall between their room and mine, while I was hiding I leaned against the back and the thin hardboard was loose, the staples holding it on were long gone, it was an old sliding front design from the 80's, I slid the back behind the wardrobe and there was the vent, I left the wardrobe door open at the point the vent joined the rooms, and that Monday night was the best one yet, it was like I was in the room with them, the voices were clear, Tash had managed to control her tears, she didn't sob once even after the second time, I was proud of her, even after masturbating 4 times listening. I tried to look through the vent but it was just black, I could see how much dirt and grime had built up inside it over the years it separated the rooms, Over the next few weeks, every chance I got I prodded the vent with pencils, a knitting needle, anything I could, and I managed to poke a few holes through the grime, some I could even see light through, although not big enough to see anything else, there were square holes around 1 centimetre square, separated by half a centimetre thick wood, with a 2 inch space between, it made it clear to me that the vent was in fact hollow and the holes could be cleared if I had the right tools for the job, I decided to try and asked my mum if I could clean my room, she asked me what I was trying to earn, thinking I had to have another motive to ask to clean my room, but I obviously couldn't tell her, anyway, I used the hoover on the carpet and when I was sure my mum wasn't watching anymore, I went to the vent, I tried a few tentative go's first, then I went to town on it, holding the release nozzle over the vent holes completely, I could hear the dust and dirt being sucked out by the hoover, what felt like a LOT of dirt, I used the knitting needle to loosen more and more, till I could see squares of light coming through, it was clear, I had to test it. I crept to my parent's room and opened the wardrobe sliding door, there was always a gap where the panels slid overlapping each other, I simply moved the gap over the vent, then I re-organised my dad's old shoes to just below the vent hole to give me a view of the bed, it wasn't perfect on the first try, but that didn't make Monday night any worse for me, it was incredible, I almost managed to orgasm 7 times, I'm not sure the last one counted, the view of my VERY pretty older 13 year old sisters ass, my dad's big cock, the perversity of it, it was incredible, my Dad had shortened the time between us going to bed and them starting their sex, which meant he could always now fit 2 fucks in the 2 hours he had Tash with him in his Room, I wanted to see more, I HAD to see more, the following week I positioned the doors wide open at the vent to see the whole Bed, I used a poster to cover it on my side of the wall so Dad couldn't see through, since it was dark my side and light his side he never noticed my eyes watching them, I masturbated furiously and came so many times I lost count, watching their naked incestuous forms in full swing, my dad seemed possessed that night, he really let Tash have it, she cried for quite a long time during, between and after both fucks she received. The next progression was I wanted a larger gap to see through, so I went in to the garage one night and found a hacksaw blade just thin enough to fit through the square holes, I placed it in the corner gap on the right of the vent and slowly drew it backwards only, cutting towards myself to keep the dust on my side, it took me a long time to get through the first piece of wood, but I didn't stop till my parents came to bed, I managed 2 cuts on my first night, and 2 on the second night, which left me with 1 square hole around an inch square, I turned my parents bedroom light on and went back to my own room, through the gap I could now clearly see the right edge of the bed, the edge my dad always bent Tash over, that Monday was by far the best yet, I saw the fuck in a new light, I even saw some of the actual penetration, OK from more than 10 feet away, and through a 1 inch gap in a wall vent, but still, it was all a boy of my age needed. It was at this time when I started to see all girls as sex objects, I began to fantasise about fucking the girls in my class in school, my teachers, even my sisters, all 3 of them took turns in my fantasies, I fucked them all every night in my dreams, Mondays I watched my father fuck my sister, over time he got more and more aggressive and Tash got more and more used to it, she didn't really cry much anymore, but she never got into it, it was just a duty she performed for dad. I looked at the hole in the vent one day, and I knew that should my parents ever move their wardrobe, they would see the vent and the new amended size hole, I couldn't really justify making the hole bigger, but then I knew I would get the blame for the hole being bigger anyway, so I decided to make it wider, I used the same blade and made 3 cuts in 2 days, the blade being quite blunt now took me a long time and some painful slips took the skin from my fingers, I kept going and the view on the following Monday was perfect, I didn't ever expect that I'd need another cut, little did I know, things were about to change again, and in a BIG way. The following Sunday I ended up in the house alone with my dad, my sisters and mum had gone to our grandparents house, I was watching TV and my dad was looking at me. "Have you started Masturbating yet?" he said, matter of factly, I really didn't want to have this conversation with my dad, but I also couldn't lie to save my life, I guessed he already knew the answer. "Yes" I said "It's totally normal for a boy of your age, so don't worry about it, what do you think about when you masturbate?" he said I was totally having the sex talk with my Dad, and I was almost cool about it, almost... But then I almost slipped up and mentioned Tash, I went Red and choked up, I couldn't talk. "It's OK Ollie, you can tell me anything, I won't get mad..... No matter WHAT it is, I promise I won't shout at you so just tell me, what you think about when you masturbate?" "It's kind of sick..... But not like.... Sick..." I stuttered and stumbled around the words "Do you think about your sister?" I almost choked, but I managed a Nod instead "Tash?" I nodded again to his one word question. "How about your other sisters, do you ever think about them too?" he said, I nodded again, I had an erection. "Do you think about doing things to them, sexual things?" he said "Yes" I said "I saw you on Monday, you had your bedroom light on, you were watching us, me and Tash. Through the wall, I saw your eyes..... How long have you been spying on us?" He said "A while" I said eventually "How long is a while?" he said, I shrugged and looked away "Months?" He said, I nodded.... My dad smiled at me. "Well, perhaps you should watch again tomorrow, see if you can see any better, but don't make any noise, we don't want Tash to hear you or notice you watching do we.... So get ready tomorrow and when I come up I will put the wardrobe door where it needs to be and you watch quietly and masturbate. OK?" He said I couldn't believe I wasn't getting in trouble for it, my dad was actively encouraging me to watch him fuck my twin sister, my 13 year old twin, he was going to fuck her tomorrow knowing I was watching. That wasn't the only surprise he had for me either, the following night, Monday, I was sent to bed at normal time, I waited till Tash went in the bedroom next door and I lifted the poster, a great rush of excitement hit me all at once and my cock grew large, right in front of me, was a 10 by 8 inch gap in the wall, my dad had removed the vent completely, just a wooden frame remained, I couldn't see anything because the wardrobe door was closed, I waited patiently, my heart pounding in my chest, when my dad came in the room it was like I was hiding in the wardrobe, he turned on the light and I could see the brightness around the door in front of me, he told Tash to move to the end of the bed and bend over it, then he opened the door, and looked straight at me, he smiled and stepped away from Tash, I could see her nightie, short and just covering her knickers at the back, my dad lifted it and showed her underwear off, he slid the nightie up over her back and over her head, but didn't remove it, then he slowly slid her underwear down, he was standing behind Tash but also next to her, so I could see everything, her blue knickers slid down her skinny white legs, revealing her pink pussy, she had way more hair than I had, but hers was thin and light, and all bunched at the front, at the bottom as I was looking at her bending over, my dad used his fingers in her pussy, she moaned but didn't move or speak, her head and arms were covered by the nightie, soon he had 2 fingers pushed right in deep, I masturbated furiously and came twice before he stopped frigging her pussy with his right hand, he pulled his fingers out and sucked them as he looked at me, I don't know why I did it, but I opened my mouth, my dad checked Tash first, her face was covered by the nightie, then he stuffed his fingers back into her deeply, frigged her for a few seconds and pulled them out, he turned to me and pushed his hand through the wardrobe and through the vent, his glistening fingers covered in my twin sisters fuck slime, I opened my mouth wide and took them both in, deep as possible, the taste was insane, bitter, sour, completely sexual, my head was swimming I felt faint, I also came, I had the biggest orgasm, a trickle of cum dribbled from my cock, my dad removed his hand and undid his jeans, kicking them off completely, then he whipped down his boxer shorts, his cock sprang free, 8 inches of impressive solid cock, he quickly stood over her, getting close, his cock was pointing down towards it's target, and he wasted no time at all, he slid it right into her, she moaned in pain as he pushed hard and relentlessly into her till he couldn't go any deeper, then he began the fuck, the most amazing thing I ever saw in my life, right in front of my face, only 4 feet away, I came at least 8 times during the next 2 hours, he fucked her twice, and in quick succession, he came on her ass the first time, a lot of white splashed up her ass and ran down her legs, I could see that he was clearly putting on a show for me, slowing down and riding her beautifully at times, but always making sure I could see her through his legs, he maintained a stance like he was riding a horse, so I could see Tash connected to him at the cock, her white legs dangling down between his, moving in time with his, her breathing and moaning in time with his thrusting, usually he would have tash take one of his cum loads in her mouth but not this week, he pulled out a second time and came on her lower back, then he rubbed it in to her. After he was finished he slid the wardrobe door across the gap silently and covered my viewpoint, I heard him cleaning Tash up and then her leaving, he came back to the wardrobe and opened the door again. "What was that like?" He said "Amazing" I said "Well, from now on you can get a proper view, and maybe someday you can join in." He said I couldn't concentrate from that second, for the next month all I could think about was fucking Tash, every time I saw her in a tight pair of shorts, or her short nighties, I just couldn't wait to watch her take it again, and I dreamed of being the one fucking her, I could literally cum just thinking about it, I had to keep leaving the room when I got an erection by looking at her. It escalated to me stealing her dirty knickers from the hamper, and sniffing them, god she smelled as good as she tasted, I did this constantly, every day as long as there was no chance of being caught, I grabbed up pairs from her bedroom floor too, the fresher the nickers, the stronger the smell of her was, I quickly upgraded smelling them to tasting them, again my head felt dizzy and my heart pounded hard, I came so many times in anticipation of doing stuff to her, It would be a long time before I got the chance, but Mondays were a special time between father and son, I watched, he fucked, and we both came, he made sure Tash always had her head and arms inside her nightie, turned inside out with her top half still trapped inside, so she could never see me watching, my dad offered me pussy slime every week and I ate it every week, it was by far the best part of Mondays, and 50 times better than sniffing her dirty underwear, I came every time the taste hit my tongue. My dad introduced a blindfold one Monday, rather than the nightie as Tash had told him she got too hot inside her nightclothes when he was fucking her, so he made her wear the blindfold, it also meant he could fuck her in any position he liked because she could see jack shit anyway, so for the following month he fucked her laying on her back, he sat on the bed and had her straddle him, he fucked her standing up one night, but most often he would bend her over the end of the bed. After 3 months, 3 whole long months since dropping the `joining in' bombshell he still hadn't broached the subject or made any progress, so I had to ask him, I waited till we were alone, in the car on the way to the betting shop on a Sunday morning. "When am I going to join in?" I said "Are you feeling impatient?" he said "No..... Just...... really want to touch her more.... Sexually...." He said "I may let you join in next week, if you can promise me something." He said "what?" I said "You have to be quiet!" he said "Of course I will" I said "No, I mean...... at the time, when you are there in the room, if you even coughed, quietly, she would know it was you, and if she freaked, which she probably would, it could all come out.... And then my life would be over, and the life you know would be over, so you have to make sure, you are VERY careful, Extra careful, not to fuck it up. Do you understand?" "I do understand" I said "And afterwards, don't tell a soul, not anyone you understand, not even your best friend as they won't get it, they won't keep quiet, no matter who it is, they will tell 1 person and they will tell 1, and so on till it gets back to me, you have to be EXTRA careful of that. Do you understand?" he said "Dad, I got it.... Honest I do, if I can keep quiet, then and after, then maybe it might happen again." I said "Of course, as long as you keep your end of the bargain" He said "So when?" I said "Tomorrow, I will take you up to bed at normal time, put the girls in bed and then take you to my room, you will sit in the wardrobe with the door closed, till I come up with Tash, then when I have her set up, I will let you out, you have to remain still till I tell you how we are going to do this, there's not much chance you will fuck her this week." I said "It's OK, I don't think I would get it in anyway, before I popped off..." I said "Before you cum.... No I don't expect you would, it will take years to control that, and some guys longer than others, some guys still pop off inside a minute when they are older than me." He said I looked at my dad with ultimate pride and total admiration as he drove, he was my hero. At 31 years old he was physically strong and good looking, my mum was beautiful too, as were my 3 sisters, I didn't think that of myself, but who does, definitely not a geeky skinny 13 year old boy who fantasises about having sex with his twin. School dragged that day, mostly because I spent a good portion of it in daydreams, I felt flushed with excitement when I got home, dinner was tense, Tash looked at my dad a few times with a little shame in her eyes, but nothing else, she was resigned to her routine now, she didn't have any choice in her mind. My mum left the house at 6:30 and said she was going for drinks after so she wasn't going to be home till late, my dad kissed her goodnight and she left, the younger girls were taken to bed at 7:30, they moaned but did as they were told, I followed my dad up saying I was tired and once the girls were tucked in he took me right to his room and opened the wardrobe door, he had covered the back again and emptied the space under the hanging clothes. "Sit here, pull your knees up, don't cross your legs or they might go to sleep and you won't be able to stand up. Just keep quiet and wait for us" he said, I was smiling to him as he closed the wardrobe door and plunged me in to darkness. 20 minutes felt like hours, my heart beating was my only company in the silence of the wardrobe till I heard a building rhythm of footsteps and then the bedroom door open, I instantly hear Tash's voice. Tash got on the bed and then waited, I heard my dad's weight make the bed squeak, at first I thought he had forgotten about me, I listened to Tash begin to moan sexually, she had been moaning sexually during their fucking for a few months, her body beginning to react to the physical presence of a cock sliding in and out of her Vagina, the squeak was fast as Dad let her have it for 10 minutes straight, my cock was hard and I wanted to watch, I was sure I could slide the door across to let me see but then I realised it was a test, my dad was testing me to see if I could resist the temptation, and I wasn't going to fail. When the squeaking stopped my dads weight got off the bed. There was a bit of movement and then my dad spoke again. "Ok, now put your hands here and hold your legs back, I'm going to eat you." He said. The door silently slid open and the light blinded me for a second, then I saw her, in all her naked glory, her long, skinny white legs pulled back to her body, her legs were held open so her pussy was displayed perfectly, the slender slit was beautiful, so clean and tidy, not a hair anywhere near it, just a little patch of thin light blonde hair on the pubic bone, the lips were bare and pretty, as the gap between them widened and the lighter inner lips came into view they were visibly wet, then the vagina entrance itself, slightly open due to the recent invader, wet all the way round the hole. "Keep very still now" Said my dad, he walked me over to the bed where Tash was and pushed on my shoulders, I kneeled right in front of her pussy, her ass was on the edge of the bed, my face was inches from her, and the smell was heavenly, much more powerful than her knickers. My dad pushed my head down, too far down to lick her, then as he stood behind me, his cock was pressing against the top of my head, he penetrated her again, it was 3 inches from my eyes, I watched as the large swollen head of his mighty shaft stretched the tiny hole in my sister wide open, and slid deep inside, he pushed till he hit the bottom and Tash let out a moan, it was so sexual, I came... right there watching I came in my pants. My dad gave her 20 good long strokes, then he pulled his cock out and rubbed the head from her hole up her slit a few times to get the entire area wet and sticky with her pussy juice, he stepped back and opened the lips of her pussy wider, her clitoris came into view, this was the first one I had EVER seen outside of Biology at school, it was small and almost white, the pink skin around was wet. My dad used his body to push my head forward, I took this as my cue and I went for it, I used the flat of my whole tongue and I licked from the hole up the slit right to the top, it was unlike any moment previous in my whole life, I felt like I was flying at that moment, the taste was supreme, she was sweeter than any sugar, more interesting than any candy, she tasted like perfection, I came again, I licked and licked, lapping the hole and swallowing mouthfuls of my saliva and her pussy slime, she moaned a LOT when I was licking her clit, I licked it hard for a few minutes and she started to shake and moan loudly, I so wanted to put my finger inside her but I resisted. My dad used 2 of his free fingers to pull my head away, I looked up at him and he nodded me out of the way, I slid back between his legs and he stepped up to her, he pushed her knees back to the bed and penetrated her again, deep, she wailed as he fucked her hard and quickly, bottoming out with force I'd never previously seen, she began to moan so loud my dad put his hand over her mouth, then he fucked her as fast as he could as she shook on the bed beneath him, he pulled out just in time and sprayed her skinny naked body with cum, Tash was shaking like a leaf, it was the most incredible thing I ever saw. My dad turned around and nodded to me to get back in the wardrobe, I went back to where I was sitting and slid the door silently across the gap. "Was that the first time you ever had an orgasm?" He asked Tash "Yeah" she said "Did you like it?" He said "It hurt when you went hard at the end, but then it felt amazing" she said "Well, I will have to make a habit of licking you before I fuck you" he said, she said nothing. "Just lay there for a while, we still have another hour" he said and he left the room, it was so tempting to open the door and see if Tash still wore the blindfold, but I knew I couldn't do it. After 10 more minutes or so my dad re-lentered the room. "Ok, on your hands and knees on the bed" he said, Tash got into position, the bed squeaked. My dad waited a second and then slid the door across again, I could see Tash again, this time from the side on all fours, the blindfold still in position, I got out of the wardrobe and moved around behind Tash, my dad had his large hard cock sticking out of his body again, erect and ready for another round. He moved me to stand next to Tash but not touching her, then he pushed his cock into her slowly, she was clearly dry so it took a long time for him to get penetration, he used his fingers on her clit, rubbing her hard and soon he was sliding his cock in and out again, his legs were slapping against Tash, she began to moan again, he fucked her as I watched for several minutes, Tash looked incredible, her bony young body was glistening with sweat after 20 minutes of fucking, she had lay her head on the bed, I was watching her face jerking as my dads cock hit the bottom of her pussy, she was moaning quite loud again, I think mostly from pain as dad was fucking her too deeply, too hard for a 13 year old pussy to take, he continued anyway till he pulled out after 25 minutes, he pushed his tongue into her from behind and she jumped from the surprise, he licked her deep for a few minutes, then he pushed a finger into her wet hole. "Your still tight on my finger, even after I fucked you for a year, you have a beautiful pussy" he said, he looked at me and I smiled, then he grabbed my right hand and my index finger, pointed it straight out and guided it towards Tash's hole, I pushed it right in, as far as it would go, till I was pushing my knuckle into her, she was Hot and Soaking wet inside, I pulled back and pushed again, I did it several times, my cock was so hard, my dad saw my erection and how wet my shorts were at the front, he pulled down my shorts, it sprang free, it was only an inch wide and about 4.5 inches long, he grabbed it and squeezed it, I didn't mind, I thought I would freak but I didn't care at all, I was happy for him to touch it as long as he let me mess with my sister, he pulled out my hand and pushed his thumb into tash, his hands were large and his thumb was about as big as my cock, he worked it in and out for a few minutes, then he moved me into position behind Tash, my Dad was bending over her when he fucked her hole, but she was perfect height for me, as dad removed his Thumb he guided my cock towards her, I pushed it in really slowly, the heat was amazing, but the tightness was incredible, it was like it was sucking me, I pushed most of the way in and then I pulled back out, I managed to fuck my sisters cunt for around 45 seconds before I knew I would cum, I pulled back and came on the bed between her legs, I faught hard to not make any noise, it was the most intense orgasm of my life, I moved back and pulled up my shorts as Dad mounted Tash again and fucked her hard, I noted the time was almost up, my dad usually stopped at around 10 Pm even if mum said she would be late, just in case, but this time he carried on, he Fucked her harder than ever, Tash was crying again, I was hard in seconds listening to my dad fucking my crying twin sister, so hard it hurt, I wanted to fuck her as hard as that, someday I would I was sure. My dad held on to Tash's hips and pulled her back as he thrust in sharp jabs, his ass hardened as he lunged forward, Tashs feet jerked in time with his pounding trusts, I could tell my dad was close because he was speeding up, for the last 30 strokes he fucked her like a piston, short hard movements, I went back to my place in the wardrobe and waited till my dad pulled out and sprayed his Cum all over Tashs back, then I drew the door closed and waited. Tash stopped crying after a few minutes, my dad didn't speak to her, just left the room and when he came back Tash was sniffing but not crying. "You said you wouldn't do it so hard anymore, you hurt me again" she sobbed "Im sorry Tash, you are so sexy, I just lost control. I will be more careful I promise" he said "I love you" he said as she sobbed, I took it from the movements and sounds they were hugging on the bed "I love you too" She said after a few minutes That was the first night of my sex life, I had my 13 year old cock inside a pussy for the first time ever, and I tasted pussy for the first time ever, I put my finger in a pussy for the first time ever, it was the best night of my whole life, and one I would never forget. I came so many times masturbating to that memory for the following week, it was a perfect night for the wank bank, I couldn't wait till Monday, my dad pulled me to one side Sunday and discussed it again. "Hay son, I know you enjoyed yourself Monday and you are doing great, I think it's important that you learn to control yourself, we don't want any cum inside your sister, she's as fertile as a goat at her age, so it's really important that we are safe, I have had a vasectomy, do you know what that is?" he said "Sure, it means you can't get anyone pregnant" he said "Well you haven't, so you could in theory get your sister pregnant, she does have periods, although they only last a day or 2 and they are not heavy yet, she will most likely be ovulating already, so we need to take precautions if you are going to fuck her on a regular basis, I managed to get this pill from the internet, it's like birth control for men, you need to take one of these every day, to ensure you don't knock up your sister, like I did to your Mum when she was 17." He said "Sure dad, no problem." I said, as I swallowed the pill "This also means, that you can come inside her if you want to, I do sometimes but I kind of like to spray it all over her, or make her swallow it." Said dad I smiled at him, I understood why he wanted to make her swallow it, because she didn't want to, dominating her and making her do things she hates, well.... It made me hard just thinking about it. "So I can do it again on Monday?" I asked "Yes sure son, as long as you don't make a sound, she'll never know" That was the start of my regular sex life, my dad spurring me on and teaching me all the way, the next change came some 6 months later, Id fucked my sister over 50 times by then, fucking 2 sometimes 3 times every Monday night, occasionally if my mum went out an Extra night, we'd get a bonus Thursday night also, Tash never seemed to care, she even had orgasms almost every time, I came inside her and took my pill every day to prevent me from getting her pregnant, Tash asked my dad a few times what he was doing while I was fucking her, she knew it wasn't his thumb, and she knew there was cum inside her, he just told her it was him and it was precum, after 6 months of this routine my dad told Tash one night that he was going to put plugs in her ears, sort of sensory deprivation, he said it would help her orgasm, he'd read it somewhere, the physical part of the fucking became the only part, she couldn't see anything or hear anything, only feel the cock or tongue, or whatever else we did to her, again she never complained, it also meant my dad could talk to me during the fucking of Tash, he'd give it to her hard, like normal these days, she'd always cum while he fucked her and he would talk filth all the time saying "Take it you fucking filthy slag, dirty little kiddy slut..." It always made me so hard, even if I'd already cum 3 times I still got hard again. I loved Fucking Tash, but I was looking more and more at my younger sisters, I wanted to abuse them, I never did anything about it, but I always wanted to, Id dream about it every night, then Id take it out on Tash on Monday nights, I would fuck her hard as I could now, slamming my thighs against her narrow ass, her firm cheeks pushing me towards climax, my teenage cock growing almost by the week now, Tash kept her pubic hair tidy and minimal, opting to shave it herself privately, knowing our father would if she didn't, her pussy never got loose, but as it grew it became less intense to fuck, she was obviously still tight, but she didn't use her body to object to the attention anymore, she welcomed it, and her juices flowed beautifully. I made her cum for the first time when I was fucking her from behind, she was moaning so loud and she started to shake, my dad was there watching, "Come on son, you've got her right there... just finish her off, hard as you can now.... Drive it in to her, fuck her son.... Slam it in hard" I increased my aggressive fucking, speeding up to force the orgasm out of her, she came and squealed, I came soon after and it all ran out of her pussy when I pulled out, my dad was right there and slammed himself in as I came out, pushing my sloppy cum back into her, he chose the same position for a while, so Tash didn't notice the change in size or technique, he kept to the same pace, but shortened the stroke, keeping back his extra 2 inches length, then he'd work her up to orgasm and just as she got the shakes he'd move up on to the bed and straddle her, holding her shoulders as he used the springiness of the mattress to bounce her back onto his cock, using his weight to push her back down again, he used a balance of pleasure and pain to keep her on the brink but not let her finish, till he was ready to cum, then he'd let her off a little, give her some nice deep strokes that pushed her over the edge, when she finished her orgasm, then he would chase his own, fucking her as hard as he could, sometimes making her cry if he was real worked up, it looked painful to watch but I couldn't wait to do it to her, when my cock was longer and thicker like dads, I couldn't want to make her cry for the first time. He pulled out and made Tash take a mouthful of cum, It was erotic to know that some of the slime around my dads cock, was my own cum, that Tash was tasting, it made me hard. Tash wasn't stupid, she eventually realised that there were 2 people in the room fucking her, she knew there were definitely 2 cocks of different size and shape, and she eventually put it together that it was me, she saw the way me and dad hung out together and did everything together, she knew it was me but she didn't ask me about it right away, she just took it every Monday till one day we were walking home from School and she brought it up. "So you haven't said anything about Dad and me for ages" she said "Yeah, well it's none of my business is it, you said you don't care and you don't want it to stop so what can I do?" I lied unconvincingly "I didn't say I didn't want it to stop, I just don't care that he does it..... Or you" she said as she looked at me, I went a little red "How long have you known?" I said "Well, I kind of guessed at first, but when dad started putting the plugs in my ears, I could still hear a little, I could hear him talking to someone when he wasn't fucking me, and I could hear you talking when my pussy was being licked so I knew there were definitely 2 people in the room, then when you started fucking me deeper, like your legs and body would touch me and I knew it wasn't dad, I guessed it was you" She said "I'm sorry Tash, I don't know how it happened, I used to watch you 2 and dad noticed, he asked me if I wanted to join in, and I did..... I always liked your body, and it was weird at first but I'm kind of hooked now" I said "Yeah, well.... Now we both know, you don't have to avoid me all the time" she said I realised there that I had stopped handing out with Tash, stopped doing everything with her, and I missed the relationship we had before I had started fucking her, although I wouldn't give up the fucking her to get it back, I did hang out with her a lot more, going to the cinema together and the mall and stuff, we even took our younger sisters out together, buying them clothes, that Monday we were in my dads room, Tash was face down on the bed with her ear plugs in and blindfold on, Dad was just getting ready to lick her. "You seem to be getting on really well lately" he said "We had a talk" I said "What about" he stopped and looked at me "She knows it's both of us, she knows what I've been doing to her" I said "Holy Fuck, really.... How?" He said "I can hear you" said Tash.... My dad almost fell backwards, Tash turned around and slid back the blindfold, she took the plugs from her ears and sat up on the bed naked, I was also naked, my erection sticking right out from my body "I've known for ages Dad, it doesn't make any difference to you fucking me does it" She said "I suppose not, but I thought you would freak" he said "Can we do this without the plugs and blindfold now?" she said, as she once again assumed the position she had been fucked in so many times before "Ok, do what you like son" he said I dropped to my knees immediately and began eating her pussy out, she moaned sexually, and for the first time ever, I made her cum by licking her, she came quickly and moaned loud, I got up and slid my cock in to her, fucking her deeply and firmly, I guessed I wouldn't make her cry anymore so I just enjoyed myself, I brought myself off using her pussy to do it, I fucked her as hard as I could and came after just 8 minutes, the knowledge that she knew it was me made me hotter than ever, I couldn't hold it off at all, I just came like crazy inside her. My dad watched and when I got down from the bed he jumped straight in and fucked her with the same force and speed I was, he lasted much longer, fucking Tash for well over half an hour, I was hard again by the time he finished, he came inside her and I jumped right in after him, Tash was moaning like crazy and came twice as we took turns fucking her, both going twice before my dad said it was time to stop. That night changed our relationship completely, we fucked in all positions, Tash became increasingly sexual, cumming hard and regularly during every Monday night marathon, my mum stayed at her friends on Friday one week after a girly night in, so she didn't have to stay sober and drive, Tash got it hard that night, we both licked her and fucked her, she let me cum in her mouth for the first time and it was 2 Am before we finally called it a night. That week on our usual walk home from school Tash asked me. "You want to fuck?" she said "When?" I said "Now, or... well... when we get home." She said "Mum will be there" I said "If we go upstairs and do homework, then we do it in your room, you have a lock on your door, we'll get our school stuff out and if mum does come up you can just say you locked it by mistake" She said "You really want to?" I said "Sure, why not.... I like fucking.... I love orgasms" she said "Sure OK" I said There were a few turning points in our relationship and this was another one, Tash and I became regular partners, every day afterschool we would get our homework out in my room on the desk and do it, then when we were finished we would fuck, sometimes on my bed, sometimes on the table, the floor, even in the wardrobe once!, it became routine eventually, and Monday nights we fucked in Dads room while he watched, then he fucked her too. For the next year, that was our routine, my cock was almost as big as dads when he decided to stop fucking Tash, he talked to both of us about birth control and being very careful once I told him we were fucking every day. My sister was my lover, all through high school and college, and even now were 20 we still meet up sometimes, neither of us bothering with relationships, just fucking as many people as often as possible, Tash was pretty much a total slut by that stage, she even let me fuck her ass on a number of occasions like my birthday and Christmas, she was stunning when she was 12, and she only got older, she's still beautiful to this day.