Yo Mama Rides Ponyboy

Listen up, buttercup. This "yo mama" zinger is all about saying your mom ain't too bright. The joke is that she tried to "ride" Ponyboy Curtis, who is a character from "The Outsiders" a novel and movie. Ponyboy is a teenage boy, not a pony. So, trying to ride him would be a dumb thing to do, which implies your mama is an idiot. And you probably are, too.