What is [what's Up You Mother Fucks]?
a way to address a room full of people, in a public and/or private place, perhaps after one of those " i just don't give a shit" days.
scene: walking into the break room after you've realized the last 4 hours you've been working have produced nothing but shit.
person 1: hey bill whats going on
person 2: bill, BILL, billy boy!
person 3: hey billy
bill: (mumbles) yeah um hum... WHAT'S UP YOU MOTHER FUCKS! hows your day asshole? Mine's turned to shit how about that? :promply walk to the vending machine grab your snack in the midst of the silence and go outside to smoke: