I don't think it counts as dirty necessarily but I went to a party with a stud I was with and during the party one of his friends kept looking at me and we playfully flirted here and there. Anyways I went to the bathroom to pee and as I am sitting on the toilet peeing someone starts messing with the door handle. I yelled that the bathroom was in use and it kept on. I was just finishing when the door unlocks and in comes his friend. With no hesitation he came in, closed the door and re-locked it, came over to me as I was standing, spun me around and bent me over. I heard his zipper go down and then I felt him push into me and he started thrusting. I had to grab the toilet tank to hold on as he went to full speed right away. He kept at it till he clamped down on my hips and I could feel him squirting inside of me. He finished, pulled out, and went over and left the bathroom. I stood there catching my breath pants still around my ankles.