my girlfriend's sister

[CAGuy0311]

I was over at my girlfriends house, and it is a pretty good size house. We had just gotten back from dinner and a movie, and were settling in to bed. Around an hour later, I heard a noise coming from downstairs. My girlfriend is a light sleeper, but I went down to check it out. My girlfriends sister was there with her boyfriend, Alex. She is a cute, petite girl, with C cup breasts. I hid behind a door, and watched as she unzipped his pants and started to work his cock. I could definitely tell she had done this before, as she worked it with such smooth and even strokes. Alex was fondling her breasts and you could tell he wanted to get under her skirt. It didn't take much for Alex to slide off her skirt and slide away her thong. This was the first time I had seen my girlfriends sister naked, and she was pretty hot. She got on him and rode him for what was like 10 minutes. I was maybe 50 feet away and I could hear his balls smacking up against her. He told her that he was ready to cum, so he pulled out and then she started to suck his cock until he came all over her face. She tried to swallow it all, but he exploded on her. Alex got dressed and left the house, and my girlfriends sister slept downstairs.

I will never look at her the same way again.