Don't you wish you had a cousin like mine!
One summer day at my cousin's house, let's call her Lisa, we were out relaxing by the pool when she asked if I minded if she took her top off to get a full-body tan. I had no objections so I said sure.
Now I have to describe my cousin! She is extremely hot and has 36D breasts and a nice ass, and is the same age as me. So she takes her bikini top off and after a while we went inside, her still with her top off, because no-one was home except us. We sat around talking when the topic turned to masturbation. She asked me if I masturbated which I said yeah and I asked her and she said that she did it whenever she got horny. Then I just had to ask her 'are you horny now?...', because while we were talking her nipples were getting harder and harder.
She said 'hell yeah' then she said that she had never seen a guy's dick, which I could believe because she was kinda nerdy but really hot. So I told her that I would show her if she masturbated for me and she agreed. She got completely naked and started to rub her clit and her nipples, moaning and groaning with pleasure. Once she reached her orgasm she let out a moaning scream as she sprayed the couch with her juices.
Once she got down from her orgasm she said it was my turn, so I took off my swimsuit and stood in front of her with my six inch dick. She asked if she could touch it and I said 'be my guest'. She started by touching it then wrapping her hand around my meat and she started to jack my dick. It felt amazing! I told her I was about to cum, as I tried to pull away, so I did not cum on her hand, but she sped up her pace and I exploded. She looked at me and smiled.
We still get together and do similar things but I will never forget that day.