My girlfriends and wife.
A lot of guys in university because I’d always have morning wood in the gym shower.
When I was younger, I had a friend that liked looking at porn mags, we were looking at some together, I asked if he wanted to see my penis, I showed him. I was only semi hard though. He showed me his, he was hard as a rock.
Guys at one gym I used to go to. Probably had an erection at least 5 times exiting the shower. Once me and my wife went together to workout, after we were done I asked that she shower and walk around naked in the change room, something she never did before. She said okay but that I had to walk around naked with a boner in the locker room. So I did. She also did as asked, she said it wasn’t too bad because there were so many other naked women in there. She did her hair while naked with three other naked ladies. She also said she was the only young woman in there with pubic hair. Everybody else was bare. Anyhow we were telling each other this at home, it made me so hard I had to put it in her right away. She was sopping wet, it slid in so easily, I ended up spraying her with so much semen it was like a second shower lol.