This is like saying fuck you
to someone, or like telling them that you dont fuck with them anymore (you dont associate with them).
This phrase is best said when somebody is trying to explain themselves to you for doing something foul
, but you literally cut them off in the middle of it by saying this.
You went and got her a big elephant even though I WAS THE ONE who found out she loves elephants and I was gonna buy her a small one for her birthday?? Thats foul, man... YOURE CUT OFF!!!