Penisweasel

A person who will interrupt a friends attemp to seduce a person of the opposite sex, just to introduce themselves and try to seduce the same person.

Taylor: Would you like to get out of here and go back to my place?

Object of Seduction: Well...

Josh: Excuse me, I'm Josh. Can I buy you a shot?

Taylor: Dammit Josh, you penisweasel