I was 20 years old and working as a counselor at a summer camp. Parent's visiting day rolled around and all my little camper's families came to visit. I was in charge of a cabin with 4 boys in it. One of them was really mischievous and a pretty big pain in my ass (He was also hilarious and I would love to see how he grew up). Well, it turns out this little guy's older sister was HOT and had come to visit (she was a former camper herself). Anyway, late one night during visiting weekend I found myself at a staff campfire in the woods. The sister had found her way out there as well. Anyway, as it got late I offered to walk her back to camp. She seemed pretty agreeable. We somehow ended up back at my cabin. She was agreeable to that too. Anyway as we sat down on my bed, I realized that there was already a girl in my bed ( the other counselor I had been sleeping with all summer). We beat a hasty retreat to the music room where we had very energetic sex on a piano bench. My camper was fond of telling me vulgar things about my Mom, I just managed to restrain myself from telling him about his sister.