A few years ago I (20 M at the time) was planning on taking a fishing trip with some family to florida. We were going to stay at my aunt and uncles house for the week. I was told I’d be sleeping in my (19 F) cousins bed. Apparently that wasn’t weird to anyone, guess would have been more weird to sleep with my dad. Anyways, weeks leading up to the trip, my cousin and I would Not allowed. We’ve always been real comfortable with each other, sometimes even too comfortable. We started kinda flirting via Not allowed. Normally I wouldn’t go for a girl like her. She’s about 5’10 and likely over 200lbs. Just a bigger girl. But for some reason the whole cousin thing was turning me on. We’d talk about sex and give stories of weird things we’ve done. I mentioned to her that one time when I was drunk I went to sleep with a girl and woke up with my dick in her ass. She asked if she should be worried that’d happen to her and I said I hope not just wake me up if so. She just laughed about it. The thought of that happening got me hard as fuck. Fast forward to being there. Spent a day fishing and drinking. Was drunk by time we got back to house. Got back to see my cousin and aunt had also been drinking. Around 2 am everyone kind of went to bed. I slept in shorts and shirt, cousin slept in large shirt and booty shorts. At one point I started spooning her and I could feel her pushing her huge ass against my dick. Nothing more than that happened until the next night.
Next night we went to bed around the same time. This time she kept complaining that her neck hurt. I offered to massage it. She laid in spoon position while I massaged her neck. Eventually I could see that my lap was within inches from her ass. I thrusted a little until my dick was poking her. I was hard as fuck. I kept thrusting and poking and she would give out little moans which would make me even harder. I mentioned I was going to have a hard time sleeping that night and she asked why. I said my shorts were too tight. She told me she wouldn’t care if I took them off. So I did. I went back to massaging her neck, this time my hard cock was out of my pee hole in my boxers. I found out shortly after I started rubbing her shoulders that she wasn’t wearing shorts under her shirt this night but rather a thong. I found this out because my dick went under the shirt and poked between her buttcheeks. She thrusted backwards when that happened, which shoved my dick further into her crack. I stopped rubbing for a second and said “ope” she asked if that was my dick. Didn’t move away, just asked. I said “yeah… should I stop” she asked me “do you want to stop” I said “no” and she thrusted more into my lap. At this point I moved my hand over her shoulder and grabbed her tits. I started thrusting in and out of her buttcrack, eventually poking her asshole. I tried shoving it in but she stopped me saying “that’s my ass” I said “oh sorry” she said “you can if you want, just wanted you to know”. I rubbed the head of my cock on her pussy for a little bit, edging it in and out, she moaned. Everything was super wet. I pushed my dick in her ass and started fucking her and grabbing her tits hard. She was getting kind of loud which worried me so I moved to her pussy. I fucked the shit out of her for a solid 30 seconds or so. The clapping of her cheeks against my lap was so loud I’m surprised nobody heard. I pulled out and came between her asscheeks. It was the best sex I’ve ever had strictly because of who it was with and the thrill of it being “taboo”. We had sex every night I was there from that point forward. Planning on taking another trip there this winter but she is engaged now so not sure how that will go.