I don't go to a gym anymore, so I only have two stories. One story was when I was visiting another gym, and I noticed a guy getting a boner. He got embarrassed and just short of leaned over, with his ass toward the shower wall, and waited for it to go away. The other story is the time I was in the shower and two young boys beside me started showering. They were both about 8 or 10 or something. The one standing right next to me just spontaneously got an erection, and then just as spontaneously it went away. I couldn't help but notice his erection because he was standing right next to me and eagerly talking to me at the time, so I was looking down at him while he was talking to me (he was a really talkative and outgoing kid). I don't think it was sexual at all, of course. Probably just a reaction to the cold or warm water, or whatever. I myself have never gotten a boner in the shower. Well, not when showering at a gym. I've probably gotten them while showering at home by myself. I think I would die of embarrassment if I got a boner in a public shower. But then, being straight, I don't really find the showers to be erotic or arousing at all.