A very extreme form of shut the fuck up, often abbreviated as UTFS. When used there is no possible comeback and the target must accept defeat no matter the circumstances
Teddy: Matt guess what
Matt: what?
Teddy: UP THE FUCKSHUT Matt:...fine...you win
Randomtroll: "OMG this guy sucks totally like this fuking commenntt !!!111!!!
Average rage user: "SHUT FUCK THE UP!"
Grammar Nazi: "Don't you mean shut the fuck up?"