the term backup peen derives from that random guy jacking off in the back of porno flicks. He's just standing there and isnt actually involved and has no input. This term is used to describe a person who has no input and is just hanging out doing nothing and is just following someone else or it can be someone on tv whos in the background and isnt involved, same thing.
"Yo when i was gonna get in a fight with BJ he had his little sidekick Frank standing next to him doing nothing, he thought he was so tough." " Yea man, god damn backup peen"
by bujeah November 12, 2003