ur mom

A maternal insult, also referred to as a "yo mama" joke, is a reference to a person's mother through the use of phrases such as "your mother" or other regional variants, frequently used to insult the target by way of their mother.

cousin sally: u got a big ahh forehead
you: yk who does got a big forehead?
cousin sally: who?
you: ur mom
cousin sally: ~goes thru all 5 stages of grief~

PS: idc if theres more stages of grief.