What is I Had Yer Grandma Last Night?
1.
It litterally means "I had sex with your grandmother last night."
It just removes the word 'sex' to make it shorter, like any other slang term.
Ryan: "Yo man, what were you doin' last night?"
Jack: "
I had yer grandma last night "
Ryan: "What the hell man?! That's sick!"
See
