I've had some of my best experiences in porn theatres.
Being a curious straight boy, I went into the theatre at the tender age of twenty just for the thrill of seeing a 12-foot cock pound a glistening teenage pussy in a public place.
However, I didn't realize at the time that porn theatres are prime cruising grounds. So I picked one of the straight movies, paid my admission fee, slouched past the hungry stares of the bears in the lobby, and slid into the darkness.
The movie was good. A young, pretty brunette with pert breasts was on her knees sucking off two larger-than-life pricks on the screen, but the theatre was packed with guys in various states of arousal. Still considering myself more straight than curious at the time, I picked a dark corner with the least panting and moaning.
Soon the girl was taking it from both ends, and my cock was swelling to burst. Trying to be discrete, I undid my fly, whipped it out, and started to stroke under my sweater. Immediately, I caught the attention of a big burly guy sitting in the row behind me. He stood up, and moved down the row to sit beside me. He kept staring at my pumping fist before releasing his own cock from his pants.