At a bar or nightclub, it is trying to hook up with, dance with, or talk to the same girl your friend is trying to hook up with. This usually results in the girl being quickly overwhelmed, freaking out, and leaving you both by yourselves.
Past tense: Roxburied.
Q: "What happened to that girl you were talking to?"
A: "Oh, Jay came over there and roxburied me. She ran away apalled, back to her huddle of friends."
followed by the agreived party singing "What is love, baby don't hurt me..." and pointing at the roxburying offender.