basically every young kids say to people as a joke
"what the fuck are you looking at" "your mum"
The ultimate insult to destroy your enemies weaknesses: no u
Fred: ur gay
Bob: do you know who else is?
Fred: no
Bob: ur mum
Fred: (gets sniped)
a joke that 12-year-old boys use, and they think they're funny.
'ur mum'
nothing else, just ur mum
What you say when you have nothing to do when you get roasted.
Well, Guess what, UR MUM
the british way of saying the classical UR MOM joke so if u say ur mum GET OUTTA HERE