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 My sister and I have always had a great relationship, probably because we
are so far apart in age.  Me and my older brother came along within 19
months of each other and my parents thought their baby days were over.  Amy
came along ten years after me, their little accident.

   While my brother and I waited until we were in our late twenties to
marry, Amy got hitched right out of high school.  She met her future
husband in seventh grade and neither of them dated anyone else.  Rob is a
good guy and, even though we all thought they were too young, we supported
their decision.

   I knew they were trying to start a family after they had been married
for two years.  Rob working for his father's company and Amy worked for him
too.  They were well set up and everything seemed fine, but they had no
luck in the baby department.  Often Amy would call me, crying, when her
period arrived showing they had failed again.

   One night they invited me over for dinner because my wife was out of
town on business and worried I would eat donuts for dinner or something as
bad.  Amy pulled out all the stops, making roast beef with all the
trimmings, which she knew was my favorite.  They were both kind of quiet
during dinner.

   Once the dishes were cleared we went into the living room for our
coffee. I had the feeling something was up from the tension I felt.

   "Joe, we have something to ask you." She started.

   "Okay.  You know I will do anything for my baby sister."

   They looked at each other, very nervous.  "It's a big favor, Joe," added
Rob.  "The biggest favor there is."

   "You know we are trying to have a baby but nothing's happening.  Rob
just got tested and it turns out he practically has no sperm count."

   I looked over at Rob.  His face was red with embarrassment.

   "I'm so sorry."

   "Well," Amy continued, "We've talked about all the options, and we don't
want some lab procedure or some random stranger..." Amy started to cry. 
Her husband put his hand on her shoulder to reassure her.

   "Joe, what we want to ask is if you would be willing to help us.  You
know..." I was stunned.  If this conversation was going where I thought it
was, then they must truly be desperate.

   Amy looked me straight in the eye and took my hand in hers.  "Joe, my
beautiful big brother, I want you to make a baby with me."

   POW!

   "We know you don't have a sperm problem.  We know you would be discreet,
and that's important to us.  Besides, you do make beautiful babies."

   He was right there.  Within five years of getting married, I had
fathered three children, two girls and a boy.

   "I don't know what to say."

   "Please say you'll help us." The look on Amy's face melted any
inhibitions I might have had.  They obviously loved each other so much that
they were willing to take this step.

   "Alright.  I feel a little weird about this."

   "We know."

   "So, how will this work?"

   "Well," Rob said, "tonight Amy is at her most fertile.  I know this
sounds a little clinical, but we have to maximize the chances."

   "I want you to make love to me, big brother.  After you're done, Rob
will fuck me so we can feel like he is a part of it."

   So now they were proposing I commit incest with her husband watching. 
This just got weirder!  Strange thing was that something inside me stirred.
I remembered watching Amy grow up, and she certainly turned out well.  I
have always been a little white bread when it came to sex, but some inner
faucet of kink had suddenly been turned on.

   "Okay, I'll do it.  I've never been watched before though."

   "I can stay out of the room if you like."

   "You do whatever you want to, Rob.  Whatever you feel you have to."

   Amy took my hand and led them to their bedroom, Rob followed behind.  I
was in a daze, realizing I was about to commit incest and adultery all at
the same time.  Once we got there Amy and Rob embraced, and I could hear
her whispering `thank you' to him over and over.  I stood off to the side
until she came over to me.

   I took her in my arms and hugged her, full of love for my sister.  She
kissed me for the first time as a lover and not a sibling.  She was
shaking, I didn't know from anticipation or nerves.  I saw that Rob had
retreated to a chair by the bed.  He forced a smile and I could only
imagine how hard this must be for him.  Amy transformed before my eyes from
sister to lover.  I reached down to cup one of her breasts as we kissed. 
Her hand went straight to the front of my slacks.  Her eyes bolted open
when she felt my hardness.

   "No wonder your wife always has a smile on her face," she whispered into
my ear.  I retreated and started to remove my clothes.  Amy took the hint
and did the same.  Underneath her dress she wore a very simple white bra
and panties.  She shucked them, and stood before me naked for the first
time since she was four.  I just stared at her for a second before removing
my boxers and joining her in the nude state.  She took my hand and led me
to her marital bed.

   Once there we kissed, her hand stroking me to maximum hardness.  I ran
my hands all over her, feeling every inch of exposed flesh.  Her skin was
so soft and warm to my touch.

   "Be gentle, Joe.  I've never been with anyone but Rob, and he isn't as
big as you."

   "Okay, sweetie.  Would you like foreplay or do you just want me to do
the job?"

   "Make love to me, Joe.  Whatever you would do with another woman, do to
me."

   Not needing any more encouragement I kissed my way down her body.  Her
nipples were already erect and after giving them a bit of attention I made
my way down to her pussy.  Much of my success with women has come from
learning early to eat pussy very well.  Word got around and the girls just
came to me, leading to many high school and college conquests.

   I licked the length of my sister's slit.  She was already very moist,
and her taste and smell was incredible.  With tongue and fingers I made
every inch of her pussy tingle, and Amy let out a chorus of animal sounds.
She was clutching her own breasts, rubbing the soft flesh in her tiny
hands. I love the look and sound of a woman having an orgasm, so my eyes
were on her face as she climaxed.  It took a bit of work to keep up with
her thrashing hips and flailing arms, but I made my little sister feel
very, very good.

   "Do you want to suck my dick, Amy?"

   "YES!"

   I got on my knees and fed my nearly nine-inch cock to her.  I knew she
had started sucking Rob off in high school and she had certainly mastered
the art.  She cupped my balls so gently while she sucked and licked my
shaft.  I could feel the sperm coming awake and didn't want to waste it in
her mouth.

   As I shifted and got between her legs, I noticed Rob had removed his
clothes and was stroking himself.  He sported a respectable seven inches,
but his meat was very skinny, just like him.  He gave me a salute as if to
grant his approval once more.

   Amy took my cock in her hand and guided it to her opening.  "Make a baby
in me, big brother."

   "I'll do my best, little sister." With that I leaned forward and suck
the first three inches into my sister's waiting pussy.  She let out a
little gasp as she moved her hips to help me penetrate her.  I took myself
in hand and worked it in.  Her pussy was incredible tight, but I got to the
point where our pubic hair met.  I looked down at her and gave her a kiss.

   "Thank you, Joe.  Thank you."

   I grabbed hold of her breasts and started to thrust in earnest, driving
it in and out of her body.  Amy put her hands on my shoulders, trying to
steady herself beneath me.  Every part of her felt so good, and the
nastyness of fucking a woman other than my wife, and trying to get her
pregnant, washed over me.  I looked down and enjoyed the sight of my cock
stretching her pussy opening.  Her flesh was red and engorged as it
accepted her brother's babymaker into her fertile womb.

   I'd like to say I went for hours, but the combination of everything
pushed me to the brink.  I started rubbing her clit as I felt my own orgasm
building beyond the point of no return.  When I heard and felt her coming I
switched to quick, rabbit-like jabs and felt my own release was imminent.

   "Here it comes!  Take it all!"

   "Knock me up, big brother!  Give me all your seed!"

   With that, I started shooting my fertile sperm into her waiting pussy. I
arched my back and held my cock right up to her cervix as I unloaded rope
after rope of my life-giving essence into her.  It was like it went on
forever, but really only lasted about a minute.

   As agreed, I pulled out immediately and Rob quickly replaced me between
Amy's legs.  He shoved his cock into her wet pussy and was so turned on he
added his dead semen to mine in under a minute.  They just lay there,
embracing and kissing and sharing the moment.  His cock stayed in her and
acted like a stopper to keep our combined juices inside her, where they
would do the most good.  After a bit he withdrew and she swung her legs
around to rest them on the wall, using gravity to aid in her mission.

   For good measure we did it two more times that night, each time Rob
would go after me so he felt part of the process.  When I left that night
they were both so grateful I thought I would cry.

   It turns out everything was successful and three weeks later Amy called
me to tell me she was finally pregnant.  Through the crying came more thank
yous, and I told her I was so happy for her.  The experience turned me on
so much that I also made my wife pregnant again, and the two of them
delivered about a week apart.  I have two more sons now, and Amy is talking
about wanting more children.
   What's a big brother to do?