look up any word, like donkey punch:
 
1.
STFUY: Shut The Fuck Up Yourself

I was in class one day and this guy turned to me and said STFU even though I wasn't saying anything, so, being the bitch I am, I said STFU yourself and it because STFUY.
Person 1: Damn, I hate your girlfriend.
Person 2: STFU!
Person 1: STFUY, you asshole, she's a bitch.
by ihrtmuzik June 15, 2012