A famous phrase that young pupils use, normally to offend the kid they said it to.
Joe Bookster: "Whats answer 19?"
Kevin Hamsterson: "Ur Mom!"
Basically a comeback for when people say anything...even if your motherless.
"Hey Gracyn how are you?..." " UR MOM"
A fat hoe with childern who are utter failures.
"Your' gay" "That's not what ur mom said last night"
NEVER GONNA GIVE YOU UP NEVER GONNA SAY GOODBYE
POV: ur mom left u at the store