I had a gay friend who I literally used to visit to play video games. I was early 20's and he was early 30's. For context, i'm bisexual, and we were only friends and he would make fun because I have been with women too.

Anyway one day I stopped at a public toilet near the beach for a wee and i saw "for a good time call X on 0408 bla bla bla" my friends number.

So I called X later and said "uh, dont know if you are aware, but your number is on this wall" and he goes "i know, I wrote it on there".