When you can't wait to get inside before you 'get inside'!!
We had had a great night and there she was stroking my cock and gettin it ready. I couldn't wait - my cock was tenting my pants! Folks weren't home, I had porch fever so fucked her on the front door step.
When a guy doesn't get to use his penis anymore either by not wanting to or not being allowed to.
female friend, "I bet he is slaughtering your pussy right now!"
Friend of female friend, "Nah he has a shelf cock. I would love him to plow me but he wants to wait a little while longer"
friend(male), "Maybe you need me to jam you for a while....?"
friend (another male mate) Maybe the idiot is gay, I'd screw you in a heartbeat!"