g'ed your mellon
You say it when someone says something stupid and someone else overhears it and can't stand it anymore.
"You just called my mom a donut? I'm gonna kill you!", heard by a kid in the hallway.
"He said my dog smells like a landfill. I'm gonna punch him.", said by a dog owner.
"She said my uncle's a chicken. I'm gonna roast her.", said by a proud uncle.