I was about 16 when I noticed that my cousin and my twin sister seemed to be almost flirtatious with each other.  The three of us grew up in a small town together.  My cousin Polly was the same age as my sister and I. Friends and family used to call us the triplets as my sister and cousin looked very much alike.  The two girls liked the idea and even went so far as making sure their hair was done the same, wearing the same clothes sometimes.  It made for some interesting situations.

My aunt and uncle lived in a very old, very large house which we all enjoyed.  The house was nearly totally encircled with large porches, both on the main level and also around the second story.  It had a full basement, too which made for lots of places to hide, explore or just have fun.  Anyway, one of many interesting features was my cousins bedroom.  Next to her room was a bathroom that also adjoined the room I stayed in.  My uncle used to call it the "Jack and Jill" bathroom.  As we were growing up this created great opportunities to catch each other naked.  Nothing really happened but it seemed as though the girls found this just as entertaining as I did.

My sister and I used to spend most of our days at our aunt and uncles house as our parents both worked a lot, with opposite shifts.  Not unusual for us to see our folks on just weekends sometimes. But anyway...this summer it seemed that maybe Polly and my sister Beth were very touchy-feely with each other.  I'd catch them at breakfast kind of playing footsie when they thought no one was looking.  At nights they'd spend time in the bathroom together.  A long time.  The bathroom door to my room was uncharecteristically being locked and they even hung a towel over the keyhole so I couldn't see in.  This was a serious breach of protocol as we'd allowed one another to spy on each other for ages.  I decided to do some investigation.

Later that night when they were done getting ready for bed I went into their room.  Not unusual.  We talked about this and that.  I was becoming very interested in my cousin.  This was the seventies and for some reason girls' pajama's were usually a baby doll kind of nighty.  Very short top, nearly (but not quite) transparent with very brief bikini panties.  Polly's pj's were actually a size or two small but she hadn't gotten around to buying new ones yet.  Sometimes when she moved around or got rather active the bottoms would shift and show almost all of one ass cheek and sometimes part of her pussy.  Beth and Polly's build was very athletic, lean almost to skinny with A cup breasts, and tight small asses.  I was pretty focused on Polly.  As usual she was sitting on her bed cross-legged.  Her bottoms had shifted, exposing a lot of skin but not her slit.  I tried to hide both the fact that I was getting hard and I was staring at her crotch.  She didn't seem to notice but it looked like the crotch of her panties had a dark spot.  I kind of wondered if she'd accidentally peed a litttle.  While we talked I sneakily moved the drapes by her bed open a little, preparing for my recon later.

I left the room quite aroused, holding a magazine I borrowed to hide my hard on.  I laid on my bed waiting until the everyone went to bed.  Then I very quietly and carefully went outside to the porch that surrounded this side of the house.  There was a full moon so I was thankful for my aunts large plants that kind of let me blend in.  I didn't need a nosy neighbor calling the cops for a prowler.  Making my way to the window I peered in.  It took me a little while to focus on what I was seeing.  My sister was kissing my cousins pussy!  They had both left their nighty tops on but had removed their bottoms.  It appeared that my sister was very good at this because Polly was really moving her hips. She suddenly lifted her ass slightly off of the bed and held my sisters head tightly to her pussy.  She remained there for a minute or so.  I knew she was having an orgasm.  I also knew I was going to sneak into their room and try to eat Polly's pussy myself. 

Sneaking back to my room with my rock hard cock I waited again on my bed.  I wanted them to settle down and go to sleep.  After a while I thought it would be worth a try.  On tip toes and moving very quietly I snuck down the hall and opened the door to their room.  It felt like I took five minutes to open the door.  Just as slowly I entered the room and closed the door.  I dropped to all fours and crawled to the bedside.  I knew that Polly always slept closest to the door so I zeroed right in.  They were both laying face down with the bedsheet covering their lower bodies.  Very gently, extremely slowly, I peeled the bed sheet back.  Great!  She hadn't put her panties back on.  Here was her naked ass! 

I very gently began by lightly touching her thigh.  I moved realy slow as I didn't want to risk her waking up and screaming or something.  It was excrutiating to move so slowly.  Gently, softly, I made my way around from her thighs to her ass and then to the inside of her thighs to her still wet pussy.  All the while checking to make sure she didn't awaken.  As I touched her wet pussy she startled me by moving.  I immediately dropped to the floor and waited.  When nothing happened I sat back up.  All that had happened was that she'd opened her legs, widely!  I started back up by gently licking around her ass, the inside of her thighs and then her pussy.  She as copiously wet.  Getting a little bolder all the time I slid my tongue into her hole.  Not being expert I spent a lot of time trying to force my tongue inside her as deep as I could.  I loved the taste of her juice.

Still not knowing quite what to do I started running my tongue from the top of her slit clear to her tight little asshole.  I was so insane with horniness at that time I think I'd have done any thing.  All through this she remained sleeping.  I felt I was incredibly lucky to be doing this with her not even knowing.  Getting much more brave I got up on the bed.  I decided to see if I could get my cock in her.  Holding myself up on my arms, being careful not to disturb my sister sleeping right next to us I poked my cock around trying to find her hole.  It slipped down a few times into her slit.  She almost imperceptibly moved her ass up and down when this happened.  It had the great effect of coating my cock with her lubricant.  On the next try my cockhead slipped in.  Very slowly, again being concerned about waking her up I pushed my cock inside of her tight body.  The combination of the tightness and velvety smoothness, coupled with her juice made me much less cautious.  I started to fuck into and out of her cunt.  I could hear the liquid noise of my cock inside of her.  I could hear the gentle slap noise as I fucked her.  Just as I was wondering what to do when I came the girl to my right, who, I was so sure was my sister, turned her head my way.  It was Polly on the right!  I had just eaten my sisters pussy and had my cock balls deep inside her.  For some reason this caused me to come instantly.  I just emptied my balls into that pussy.  It remains one of the most intense cums I've ever had.  I continued to fuck her as now our juices mixed.  Her lube and my come.  It felt fantastic.  I was so turned on that I didn't get soft.  I continued to fuck her for a second orgasm which I also left inside of her. 

Slowly pulling my cock from her I left the bedroom the same way I entered.  Laying on my bed with my cock still hard and covered with my sisters juice and my cum I wondered if she would know  and if she did, what would she say.  Breakfast the next morning gave me the answer.  Both my cousin and sister were downstairs still in their pj's.  Still no bottoms.  Aunt and uncle were gone so they felt pretty brave in teasing my this way.  Years later my sister admitted to having to talk Polly into it.  They just moved around the kitchen acting like they didn't know they weren't wearing their bottoms.  This of course drove me crazy.  It was also the start of a lot of fucking my sister while she was "asleep".