1. one of your friends who steal's your girlfriend, make's out with her, and proceeds to have sex with her.
2. the friend of yours who is a jerk and might be secretly gay.
"Dude, I'm sorry I stole your girl. I was a real chap's dick."
"Man, you look hot tonight. Let's get out of here, this place sucks."
"Geez dude, are you gay or something? Don't be a chap's dick."