Note: This story was dynamically reformatted for online reading convenience.
 
 Snooping sister 4

   The next weeks Nilla and Pat avoided each other like they needed to take
a break from what happened but Pat could sense that Nilla continued with
her sexual abuse of her younger sister.  It was not so obvious these weeks
because Nilla door always was securely closed during these weeks but Pat
could hear Cathys cries of both agony and pleasure now and then through the
door.  She did not dare to taken it up with Nilla again after the way she
had been demoralised before.  Pat just did as she did after the weekend
when she and Gina used Winnie and Nilla.  She ignored what was going on, as
if she did not react to Nillas constant domination of her younger sister,
it did not exist.  But it was happening inside her home and it escalated
during these weeks after the showdown in the kitchen.  Nilla got more
elaborate in her ways to push Cathy to sexual acts and she got more
dominating in her actions.  But even if she made Cathy do more advanced
sexual plays she always made sure that her sister got her share of orgasms
out of these plays.  So these weeks Cathy got tied up, whipped, denied
orgasms, forced to orgasm and of course fucked in the ass which she loved.
One night the first weekend after kitchen incident Nilla even tied Cathys
head to her pussy so she had to lick Nilla all night until she fell asleep
of exhaustion.  She slept only a short time before Nilla slapped her head
demanding more tongue action.  That night she really became her sisters
slut pet and after that Nilla could do anything to Cathy.

   Nilla moulded Cathy for another week before she continued her plan for
her mother.  By now Cathy was so good in licking pussy that Nilla longed
until she could come home and have her between the legs.  Cathy on the
other hand longed to get home and worship her older sisters cunt and her
slit got wet when she tried to predict what her sister would do to her. 
She was addicted to the sex and to be dominated.  At twelve years of age
she was in the hand of an sexual predator who happend to be her sister but
this was not the end.  It would get worse.  In the middle of the second
week Nilla had whipped Cathys tits and pussy a long time upstairs in her
room and kept on doing that when their mum got home and during her cooking
dinner.  Just before dinner Nillas put rubberbands around Cathys nipple and
put on panties that was two sizes to small.  Inside Cathys panties Nilla
placed the vibrating egg lodged against Cathys clit and made her put on
shorts on top so it could not be seen.  Then she selected an tight shirt
that showed Cathy nipple portruding through but not showing the
rubberbands. Cathys tits and pussy was all hot from the whipping and her
nipples hurt from the rubberbands.  Nilla tested the egg and Cathy jumped
when the egg started to vibrate.  -Tsk tsk, slut pet, how do you think you
will get through dinner if you are this sensitive?  -You cant orgasm in
front of our mum, can you?

   Cathy shook her head no but felt extremely aroused of the thought that
she might happen to cum in front of her mum.  But that was just what Nilla
planned to have Cathy do and she was certain to get more than one out of
her.  This was going to be an blast.  Her mother would ignore it and Cathy
would try to fight it but both would loose.  -Slut pet, tonight I am going
to fuck your ass in your own bed just to show you that I love you.  -But
first lets grab a bite to eat.  Cathys pussy moistened of the thought that
Nilla would fuck her ass and in her own room.  She loved assfucking but had
never gotten it in her own room.  When they came into the kitchen Pat
almost dropped the deep dish with mashed potatoes she had in her hand when
she saw how her youngest nipples poked through her shirt.  Pat immidiate
thought.  -They have had sex that is why Cathys nipples are so visible. 
Pat got aroused herself but as Nilla predicted just ignored that her
youngest daughter sat at the table and showed her nipples.  Usually Cathy
and Nilla sat at one side of the table and Pat at the other but this day
Nilla sat down in a chair beside Pat.  Nilla pulled her plate and glass
over to her side and took some food.  At first it looked to be an dinner as
usual if you did not count Cathys nipples but after a while Cathy began
fidgeting.  Nilla had put the egg on slowest vibration and it had its
effect on Cathy immidiately.

   Amazingly her nipples got even more visibel and a slight blush crept up
her face.  Nilla had finished her food in double speed and turned her chair
slightly towards her mum and then put her foot on her seat.  Nilla turned
up the speed of the egg and Cathy grunted a low moan and by that drawing a
suspicious look from her mother.  Cathy tried desperatly to get control
over her body but as if Nilla knew what happened she turned up the speed
again.  This time the moan was clearly hearable and Pat asked.  -What is
the matter, honey?  Cathy raked her brain and said.  -I have cramps in my
stomach, uuhh.  Nilla pushed up the speed even more and now Cathy could not
hide her excitement.  Nilla put her foot on her mothers lap and rubbed
slowly closer and closer to Pats mound.  Pat had sweatpants on and they did
not give much protection.  She also knew now why Cathy behaved so strange.
Somehow Nilla had a way to make her sister excited and her foot was on the
same mission.  Pat decided to stand up but when she tried Nilla just pushed
hard on her mound with her heel and also increasing the speed for Cathy
making her cry out.  Pat looked over the table and Cathy sat with her mouth
open and her fingers squeezing so at the table that they where white.  The
eyes rolled back and forth in Cathys head and a guttural groan came from
her mouth.  Her eyes did not longer see anything but her mother was
consumed by the sight of Cathys on going struggle.

   Nilla pushed her chair close to her mothers and put her left hand inside
the sweatpants.  She began an idle caressing of the folds of her mothers
slit while she whispered.  -Slut pet is going to cum and it will be an
massive one.  -The more stressed situation and more embarrassing it is the
harder slut pet climaxes.  -And I can tell this is going to be one of the
biggest she has had ever.  Cathys breath was ragged and her head lolled as
she got closer to an climax.  -Look at her, mummy whore.  -Is she not
beautiful?  Nilla kissed her mother on the cheek and fiddled with her clit.
Then with a piercing cry Cathy orgasmed.  -Aaaiiiiiuuhh aaarrhhh aarrgghh.
Pat watched closely at her daughter shivering and moaning through her
climax and did not see that Nilla put a remote on the table before she
whispered in the ear.  -It is on 70% of its speed and you can decrease or
increase the speed.  -If you decide to decrease the speed it will be over
but if you increase the speed slut pet will go from this orgasm to the
next. -What are you gonna do?  Pat looked at the remote and saw speed
showing just under 70%.  -Do your move now.  Nilla fiddled with her mums
clit so she also neared climax and with joy she saw her mother finger push
on the increasing speed and it jumped to 85%.  Again Cathy screamed and as
the orgasmed run through her body she sat and rocked on her chair.  Pat
climaxed with an loud groan and her head slumped forward but Nilla grabbed
her hair and said.  -Look at slut pet, she is ready for another one.

   Without Nilla saying anything Pat pushed the increase button on the
remote and Cathy got ballistic.  It was a soulsearching scream that came
out of Cathy and her whole body spasmed and jerked.  -Oouurrgg aarrgghh
oouugghh.  Pat came with own scream but it was much lower than Cathys. 
-Ouuh fuuucck.  Nilla took her hand out of her mother sweatpants and licked
the fingers.  Then she took the remote and closed it before Cathy passed
out.  Both Nilla and Pat watched as Cathy slowly calmed down, still
trembling and shaking.  When Cathy was all calm she could not look her
mother in the eye but she heard her say.  -That was some major cramps. 
Cathy wanted to sink through the floor but Nilla just laughed.  The rest of
dinner was done in silence and after all gathered in the living room to
look at tv.  All the time Nilla played little with the remote but never so
much that she risked Cathy to cum.  She wanted to save that to later,
hopefully with their horny mum watching.  Around eight Nilla said that she
was going to her room and Cathy said she would do the same.  Nilla kissed
her mum goodnight and whispered in her ear.  -It is a show in Cathys room
at ten and it will be a good one.  Pat sat and watched tv but could not
concentrate on what was on it.  When the clock neared ten she went upstairs
to her room that was just opposite Cathys room.  Pat went inside her room
and waited by the door and ten she saw her older daughter come walking with
a strap on to her waist.

   Nilla pushed her mum door open and grinned when she saw her standing
inside the doorway.  -I see you are game for it.  Nilla turned and opened
Cathy door and walked in leaving it all open.  She heard Nilla talk with
Cathy and slowly she crept up to the doorway.  Cathy was on her stomach on
the bed all naked and Pat could see her behind with a hint of pussy under.
-Are you not going to close the door?  -Why, slut pet, would I do that? 
-So our mum dont see us.  -You did not think of that during dinner as you
came like the slut whore you are right in the face of your mother.  Cathy
blushed but Pat never saw that.  -I could not help it and you know that. 
-I cum so easy when I have something buzzing at my clit.  -Yes I know, slut
pet.  Pat saw Nilla slowly push the dildo inside Cathys ass and she heard a
loud grunt from her as it bottomed.  - Slut pet, you can be as loud as you
want.  -Today I dont give a damn about mummy whore.  Nilla wedged her feet
on the inside of Cathys legs and pried them apart and then began to fuck
her younger sister.  Pat had an excellent wiev of the dildo plunging in and
out of her youngest daughter and the slit under who gaped at every push
inside.

   Pat admired Nillas athletic body as she took a hold of both shoulders of
Cathy during her assfucking.  -Ouuhhmm.  -Yeah, is it not nice, slut pet?
-Yeesss.  -Downstairs in the kitchen your mother came twice as she watched
you orgasm.  Nilla pounded harder into Cathys ass and pulled her head back
by grabbing and pulling back.  -Oouucchh.  - I fingered mummy whore all the
time as you climaxed in the kitchen but it was mummy whore who raised the
speed of your vibrator.  -Ohh shiitt.  -Did you like to cum in front of
mummy whore?  -Ooohh yeesss.  Now Nilla was almost bounching on Cathys ass,
slapping her hip against her asscheeks and drawing loud moans out of her.
-Do you love me, slut pet?  -Yyeeaass oouuhhmm.  -Do you love my
asspounding?  -Oh yeaaahh.  Do you mind that mummy whore is watching me
fucking your ass?  -Ooihh nnooouuhh.  -You may cum, slut pet.  Cathy
screamed her orgasm out in the room.  -Aaauugghh oouuhh oohh.  But Nilla
did not stop.  She just kept on pounding her sisters ass.  She sprayed some
lubricant in the crack and then kept up her fucking.  -I bet mummy whore
has her hand inside her panties and fingers her cunt while she looks at us.
-Ohh god.

   Now Nilla was viciously fucking her younger sister and pinched one
nipple hard.  -Two more weekends before we go to Gina and Winnie pig to
fuck but before that I have to fuck your pussy first so that you are ready.
-I am going to tie you up and blindfold you and then fuck that tight pussy
of yours.  -Do you like that idea.  -Yeah oh god yeah.  -And from now on we
are going to fuck more openly to let mummy whore watch as much as that
horny bitch want.  -Oohh.  -Do you know what?  -I would like to see if not
your slutty friend Amy is ready to have her pussy munched soon.  -How about
we try to set that up.  -Oohh fuuuckk yeesss.  -You and me have to discuss
how we get slutty Amy to participate but we take that later.  -Now we fuck
harder.  Nilla lifted Cathy up on her four limbs and speeded up her
fucking. -Oohh shiit.  Pat could see Nilla body glister from sweat and
Cathys head that twisted from side to side.  Pat fingered her clit hard and
came in an thunderous orgasm that made her moan right out.  Cathy and Nilla
heard that and both got more frantic at their fucking.  -Mummy whore just
diddled herself to heaven.  -Ouumm mummy whore.  It was the first time
Cathy used her mother degrading name but jumped to the opportunity to get
her to say it more.  -Who is diddling her clit?  -Uuhh mummy whore.  -Who
likes to see us fuck.  -Ohh shiit mummy whore.  -And whos pussy will you
lick?  -Arrggh god mummyyy whooreess.

   Cathy orgasmed while screaming.  Nilla pulled out of Cathy ass and
slapped her sisters pussy several times and then striped out of the strap
on and got in front of her sister to lay down.  -Lick my pussy slut pet. 
Cathy bowed her head so she could glance back and saw her mother with her
hand inside the pants and thought.  -Nilla is right, mummy whore likes
this. Then Cathy decided to let her mother realise what a good licker she
was and began to service her sister.  Cathy knew what Nilla liked and how
to get her off fast but was determined to prolong her ministration of
sister cunt.  All to give her mum an good show.  She brought Nilla to the
brink of orgasm several times but always backed out before she could climax
and after thirty minutes of teasing Nilla could not take it anymore.  She
grabbed her sisters head and mashed into her cunt and rubbed against it
hard.  Nilla came with a groan.  -Oooumhh, slut pet.  Nilla kept pumping
her pussy at Cathys face and shortly after first orgasm she climaxed again
and she praised her sister.  -Slut pet, I think mummy whore will think
about how good this looks and wonder how good it feels.  -Now kiss pussy
goodbye.  When Nilla got out of the bed Pat disappeared into her own room.
Before going to sleep that night Pat masturbated to another climax reliving
the scene from inside her daughters room.