What is Yo Mama?
A term that originated in street diming which precedes an inventive insult to the other person's mother. Presumably because once upon a time, in the 'hood, Mothers were highly prized.
"Yo mama" so fat, she have to go downstairs sideways.
meaning: your mother
"yo mama" is on her way home
An derisive term, equivalent to
Thug #1: I will cut you up!
Thug #2 : "yo mama"."
Thug #1 swings and the fight is on.