It is when a guy slathers peanut butter all over his genitals and puts his pants back on until his girlfriend comes home. He then pulls down his pants and treats her like a dog.
When you're letting the family dog lick peanut butter off your dick, and your sister walks in before you can finish, so you pound her ass with your still peanut butter covered dick.
Sophia walked in on me and Daisy yesterday, so I had to give her a peanut butter slammer.