I was 19 i was at my girlfriends lake house for the 4 of july. all day everyone is drinking out on the lake. her best friend is there and she is smokin hot. she has such a fat ass and i was staring at it in her bikini all day. my girlfriend's friend is so easy and we flirt with eachother all the time. it is night now i am sleeping in a room by myslef and my gf and her friend are sleeping upstairs. its like 1 or 2 in the am and i cant sleep and still kind of drunk. i hear someone come from upstairs and go to the bathroom and walk slowly outside my door. the door opens and i think its my gf but its her friend. she was drunk too and i said hello she said nothing and hopped on top of me and started making out with me.were both worried about my gf so we decide to go outside to the lake. we grab some beers from the cooler and walk over to the private beach area were nobody can see. we end up having sex on the sand and i ejaculated inside her. we both went to bed. the next day on the lake we are eyeing eachother all day and i can tell she wants more. later the next night its raining out so we went outside to this tent that was set up and there was an air mattress and we fucked again to the sound of rain. she really knows how to ride the D