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 My older sister and I are both in our 50s.  I'm divorced and my sister, who
is about two years younger than me, has been a widow for about a year.  I'm
currently unemployed.  A short time ago, she asked if I could help her
clean out the summer cabin she and her late husband owned for years in a
nice secluded place along a river bank in the countryside.

   I hadn't seen my sister -- her name is Molly -- since her husband's
funeral.  She's around 5'5" and has long, shoulder-length dark brown hair
that now has some streaks of gray.  Like me, she has put on some pounds in
her late middle age.  Despite the weight, she had a figure that can be
described as Rubenesque, very curvy, with a saggy but full bosom and nice
round hips.  Molly's eyes still have the sparkle I remember from when we
were younger and full lips that are still a nice natural rose-red.

   The day I showed up was rather hot.  I spent some time cleaning out a
very dirty and junk-filled shed.  The heat was building inside and I was
soon covered in sweat and dust.  Molly stuck her head in and saw the mess I
was dealing with and how dirty I was.  She suggested I take a break, cool
off and take a swim in the river.  I told her I didn't have a bathing suit.
She said it doesn't matter.  She and her husband used to swim nude all the
time.

   Since the river bank was just a few yards from the cabin, I just shed my
clothes near some patio chairs and took a dip.  When I came out of the
river, my sister was waiting for me by one of the chairs with a nice cold
beer.  Trying to act nonchalant about the fact that I was completely nude,
I thanked her for the beer and sat in the chair, letting the warm sun dry
me off.  My sister sat in the chair next to me and we chatted as we both
sipped on our beers.

   I remember glancing over and looking at Molly and her body more closely.
Her shirt was partially unbuttoned -- because of the heat -- and I could
see the swell of her breasts and cleavage quite clearly.  I tried to stop
glancing because now my cock was stirring, fully exposed.  The more I tried
to distract myself, the worse it got.

   Then my sister noticed.  She smiled and said something like, "damn Jim,
you are pretty good sized." I know I blushed and said she wasn't so bad
looking herself.  We both kind of laughed and agreed that it had been a
while since we had been with a member of the opposite sex.  Molly said she
hadn't seen a naked man since well before her husband died.

   And then she reached over and began to fondle my cock.  At first I
thought she was just tickling and teasing me.  But then I saw that look in
eyes that I've seen other women get when they start to feel horny -- the
same look guys get when they see a woman's tits or ass.  The next thing I
knew, Molly was kneeling between my legs and stroking my cock.  I looked at
her and now could see her breasts clearly as the top of her shirt bulged
open with her ample bosom starting to spill out.  I protested, but it was
very meek.  Instead of trying to stop my sister, I just leaned back in the
chair, my heart pounding hard, the cold beer in my hand was getting warmer.

   It didn't take long.  Between the buzz from the beer, the warm sun, the
taboo excitement of my sister stroking my cock, I had little self control
and began spurting.  Molly smiled and let out a sigh of satisfaction.  She
then licked her fingers and winked at me.  I stumbled to my feet and said I
needed another dip to cool off.  She laughed at my remark.

   The rest of the day went by without incident and we had small talk
during dinner.  I said I was tired -- and I was from the physical work --
and was going to bed.  But as soon as I hit the bed, I just tossed and
turned unable to sleep.  Too much was on my mind from the afternoon.

   And then I heard a small knock on my door and my sister stepped in.  She
looked a little nervous, or excited, and asked me if I was feeling as horny
as she did.  I didn't disagree and pulled back the bed sheet.  Molly came
over and pulled down my boxer shorts.  I was quickly getting erect and
without much foreplay, my sister straddled me and we were fucking.  It was
dark, so I couldn't see much and my sister had a long t-shirt on for a
nightie.

   Molly was right.  She was horny.  She rocked slowly back and forth and
within 30 to 60 seconds she started having an orgasm, moaning as she did. I
was just as aroused and didn't last much longer.  When I finished, Molly
started to dismount, but I asked her to stay, so she kind of sat on the
edge of the bed.  I reached out and lifted her night shirt off so she was
completely naked now.

   I caressed her breasts and she massaged my cock.  We sat there, not
talking, just feeling each other, breathing heavily.  Within a couple of
minutes I was hard again and so I gently moved Molly so she was lying on
the bed.  I opened her legs and lay between them, slipping back into her
very wet pussy.

   We fucked like that, and after resting I got behind her and fucked her
from behind.  I can't remember the last time I had sex and orgasmed three
times in one night.  I was absolutely exhausted, exhilarated and unsettled
about what had just happened.

   We feel asleep together and I woke up at dawn to find my sister was
spooning me, her arm draped over my body.  I gently turned over and looked
at Molly.  She always had a pretty face, but like me, age had taken its
toll.  We both had put on weight and now I could see the rolls of flesh on
my sister, the sag of her breasts, the broadness of her hips and ass.  But
it was all powerfully erotic and attractive.

   My sister Molly began to wake up.  I smiled at her, feeling both excited
and nervous, still not quite sure what had happened or what it was going.
She smiled back, teasing me about my virility.

   "I didn't realize something so taboo could be so exciting," I replied.

   "We're adults, Jim.  Nothing taboo about what we did, expect that we're
brother and sister," she said.

   I said nothing but started to gently stroke her.  Molly rolled over a
little so I could have better access to her plump body.  Then I impulsively
kissed her.  I started to pull away, thinking I had gone too far, but she
pulled me back in and we kissed longer and with more passion, like two
lovers.

   And then we were locked in a deep embrace.  I felt my cock stiffen once
again.  I rolled on top of Molly and entered her quickly.  She responded by
wrapping her legs tightly around my waist, holding me tightly.  We kept
kissing as we fucked furiously.  Both our bodies rocking and thrusting. 
Molly grunted with every thrust I made into her.  It was unbridled lust
now, our bodies exposed in the light of the morning, and our passion still
on fire despite a night of sex.

   We both orgasmed almost simultaneously, but I kept my hips going,
pushing my cock in and out, pounding hard until she cried out and climaxed
again.

   When I looked down at my sister, she had tears in her eyes.  I kissed
her again.  She smiled.  "I never realized how much I missed being with a
man, especially one I cared for so much," she murmured.  I told her I felt
the same and would be very happy to fulfill that very special physical and
spiritual need we both craved as brother and sister.