prime the pipe

Before you go out to a singles bar masturbate before you get a piece of ass, this would prolong the experience for her and save you the embarrassment of not going a long time with her.

Dude - " Hey Johnny let's go out to the Juke Joint what do you say?" Johnny- "I'm down with that but you know I got to Prime the pipe first there bro"! yeah right like he is going to tell his friend that he is going to jack off.