My weeks stay in my cousin's New York apartment, turned into sex with his live in girlfriend. I was 16, in my high school summer vacation staying with them while my parents took a weeks tour to Mexico. Most days were spent with Anita while my cousin worked. A beautiful 19 year old girl walking around the apartment in skimpy clothing almost see through. Even had thought that she was flaunting her goodies intentionally to arouse me. More than once I saw her bending over giving me a perfect view of her perky breasts down the front of her nighty. Spent the first two days getting erection over her sexy legs, pink nipples and rubbing off a few times. Went back and forth thinking if she was trying to seduce me or it was just my imagination. One day she asked if I wanted to sun bath on the roof. Told her I didn't have a swim suit. "No problem" she said, handing me one of my cousin's swim suit that had to be held up with a wooden clothes line pin. We went up to the roof with towels, bottle of sun tan oil and feeling my dick getting hard over her extra small bikini that left very little to the imagination. Covering my half hardening dick didn't do much to go un noticed. I just froze as her hand slid down the front of my swim suit popping the clothes pin, sending my swim suit sliding down my legs and felt her hand firmly rapped around my dick. "I won't say anything if you keep quiet" as I stood there totally naked feeling worms of her mouth around my dick. It was a mixture between shock, total pleasure and scared of being seen and the realizing I could never speak a word about it. Ended up with my head guided between her legs, face cover in pussy juice going to lunch on a beautiful sexy girl that didn't belong to me. I came twice in her mouth that day and that's not even counting the times we fooled around on the kitchen floor. In fact spent most of the following days sucking her breasts and pussy and enjoying getting sucked off but always feeling guilty and scared of my cousin finding out.