Used to describe someone who is wants to start an argueement or a fight. They pick on something, this is known as bridging up.
When asked "why are you bridging up?" can lighten a situation, and make it humourous. Therefore, avoid a fight.
Person 1: Why you bridging up for?
Person 2: Coz I know I can put it over you
Person 1: What the fuck do you want?
Person 2: Why you bridging up for?