The phrase is: to go psycho on someone. It is another way to say "go crazy on someone." It can mean anything from a person yelling at someone or a person throwing things at someone. It comes from the word "psychotic." If your friend has a fight with her boyfriend for example, she might say, "He went psycho on me when I told him I wanted to break up." Another way to say it would be, "He reacted like a crazy person when I told him I wanted to break up."

Going psycho Yes. It basically means you will "freak out" and go crazy. It definitely involves anger and may or may not involve violence. Synonyms: freak out go off lose it blow a gasket blow one's mind blow one's stack blow one's top crack up flip one's lid flip out fly off the handle go ballistic go bananas go batty go berserk go bonkers go buggy go cuckoo go daffy go haywire go kooky go loco go loony go mental go nuts go nutty go off one's rocker go off the deep end go off the wall go wacko go wacky lose control of oneself lose one's cool