i've had sex with a girl infront of her parents without them knowing.

we had a blanket on and i was on the couch. she was sitting in my lap and my dick was inside her. both our pants were about a quarter of the way down. we were all watching a movie together. her parents went in their room towards the end and we finished up and pulled out.

other than that, we've done it out in the open country by a lake. the only thing that made that horrible was all the mosquitoes and insects.

most of the other times were on a couch/bed/floor/in a car.