I was 21 and she was 18. It was a random weekend and i had some friends over for a bonfire. Mf gf asked if she could invite her cousin which i said yes to. Everyone was there. And we were outside playing a drinking game. And I barely knew her cousin, barely heard her talk, but the more we played and the more she drank, the more she talked and very subtly sent hints my way. She sat with me and my gf on a bench, the three of us all thigh to thigh with me in the middle, would constantly lay her head on my shoulder then blame it on the alcohol. And at one point pulled a card which she read “the person to your left has to kiss or slap you” but what it actually said was “the person across from you”. I was to her left and of course my drunk friend started egging me oh too kiss her which i know she wanted by her smirk and face. But bc my gf was there i just very lightly slapped her, pretty much a tap but giving her a wink and smirk. Later in that game i made a joke that my gf didn’t find very amusing and she stormed off to my bedroom for the rest of the night. After that the rest of us got in the hot tub where her cousin was glued to my side the whole time, so I said fuck it and eventually put my arm around her and pulled her a bit tighter. By the time we got out we were all drunk and we paired off, me and her cousin went into the laundry room to grab clothes and she just began changing in front of me, taking her top off, Then i dont know if this was on purpose or what but she dropped her hai tie she bent directly at the waist, pushing her bubble butt out. As soon as i looked down at it she tookk a couple steps back and pressed her ass right against my stiffening cock