It was my sister's 18th birthday, and she had only recently split up with her boyfriend of 3 years. To drown her sorrows, she had arranged for her and a group of her friends to go out clubbing for the night, and party away to the small hours. Naturally, she invited her big brother, and I snapped up the offer - the club in question was always full of fit young things.
Sara and I had not always been close - when we were in our early teens, I had been a bit of a bully towards her, and we had spent more time arguing than anything else. But as we started to grow up a bit, we became fast friends.
I remember one day, we were at home by ourselves, and we decided to play "mummies and daddies". An innocent, childish game that comes naturally to most young children. But when "mummy" came home from work, and she and "daddy" went to bed...well, let's just say it was an arousing experience, albeit rather disturbingly so.
Anyway, back to the night in question...we were at the club for some hours, and the beer was flowing freely. A couple of Sara's friends were eyeing me up, and as I drank more I began to feel more and more confident that I would be taking one of them home - or, who knows, maybe more than one! I decided to try and evoke some jealousy in them, by asking my sister for a dance. She accepted, and we walked over to the dance floor, laughing and chatting on the way.
We boogied for quite a while, with her friends watching, and I was really enjoying myself. Then, the DJ put on a slow song, and I started to walk off the dance floor, but my sister caught me by the arm and pulled me back, wrapping her arms around my neck and moving her body close to mine as she slowly gyrated to the music. I was more than a little shocked, not least because I was extremely aroused at the idea of my sister being so close. I concluded that I may as well enjoy the moment, as it would probably never happen again, so I relaxed and put my arms around her waist, resting one hand on her arse. All sorts of wicked (and definitely wrong) thoughts were racing through my mind, aided by the alcohol, and I found it hard to concentrate on the fact that this was my sister.
At this point, my memory goes blank, and I don't remember what else happened at the club, or when/how I got home. We were both living with my parents at the time, but when I woke up the next morning I did not recognise where I was. As the sleep receded from my mind and my eyes, I looked around, and realised that I was in my sister's room! Slowly I looked to my left, and there beside me in the bed was Sara. My breath caught in my throat as I tried to take this in...I was in bed with my sister! I lifted the duvet slightly, and confirmed that we were both naked. I was speechless, even inside my head...What had happened? I wanted to know, but try as I might I could not remember...
I lay there a while, pondering the situation, when Sara began to stir in her sleep. She rolled over, laid her head and one arm on my chest, and settled again. I could feel the swell of her breasts against my side, and it was incredibly erotic. I began to regret, not what may have happened, but that I could not remember it. I had bedded my sister, and had no memory of it whatsoever!
After about 20 minutes, Sara moved again, and this time she came out of her slumber. I watched her carefully as she went through the same thought process as I had - the slow and shocking realisation of who she was in bed with. She looked up at me, alarm evident on her face. Neither of us said anything for some minutes, both overcome with shame at what we had obviously done.
Then she broke the silence. "What happened last night? I don't remember coming home..."
