To use ones balls as an offensive weapon, slapping your victim across the face. Think of it as a violent teabag. This action can be applied in a variety of situations, such as when drunk, angry or enjoying a good streak.
John: Dude, my balls are hurting something chronic this morning.
Jack: Why's that?
John: Joan refused to swallow last night, so I totally duck slapped her.
Jack: Brutal man, brutal.