the most hilarious thing to ever be said
amanda:"hey emma what are you doing tonight?"
emma:"ya mum in a milk bar
ya mum is what people usually say when they can't think of any comebacks
person1: whatcha doing?
person 2: ya mum
Usually used in a sentence involving yer friend banging her
Guess who I had sex with last night? Ya Mum!
awesome comeback for lowlifes who have no other decent insult to use
Fred: What's the time, man?
Jess: YA MUM!