A few years ago, while visiting London, I was staying at a hostel.
After taking a shower in the bathroom of the floor that I was staying on, I moved over to a cubicle with a door to get dressed.
After taking my towel off and standing there naked I became aroused and slowly started to stroke my cock. But instead of closing the cubicle door I decided to keep it open because the risk of getting caught was so exciting.
After a few minutes I was really getting in to it and couldn't have cared less if someone walked in. Just then a guy (late 20's or so)walked in. I just looked at him and kept on stroking, now even more turned on. Neither one of us said anything to each other and he stood there watching me as I put on a show for him, really fucking my hand.
He was rubbing his cock through his pants and after another minute or two I came all over my hand. He looked at me, nodded, I nodded back, then closed the cubicle and finished getting dressed.
Never saw him again. That was fun.