This phrase is used (mostly in England) as one of the best way to end a conversation. The reason for this is because there is no way to reply to it.
Example 1:
Joe: What do you want for dinner tonight?
Jeff: Ur mum
Example 2:
Bob: Harry youβre so ugly
Harry: Ur mum
Example 3:
Teacher: Harvey, did you do your homework?
Harvey: No
Teacher: Why not?
Harvey: Ur mum
the words 'ur mum' are the greatest words mankind has ever invented. There is so much emotion in these beautiful words I cannot even describe how it makes me feel when someone whispers these words Into my ears it makes me feel all buzzy and tingly it is a sensational feel coursing through your body. the maker of these words a quandarius figgle bottom the 3rd now he is the most gorgeous person to ever set foot on this earth gosh I wish he would marry me.
jack: Hey christian ur mum is a fucking ugly whore.
Christian: shut up cuz guess what I had intercourse with ur dad last night
jack: wha-
Someone British trying to roast you, but it doesn't sound good because they can't say ur mom.
British person: Ur mum is weird.
Me: Stop trying to roast my "mum".
2π 1π
The way to answer anything or start an insult, it's even better if who you're talking to doesn't have a mom or their mom is dead.
mainstream kid: Hey what's your favorite fortnite skin?
me irl: ur mum xdddd
kid: M-my mom is dead.... *breaks into tears*
me irl: tHaTs HiLaRiOuS *does fortnite default dance*
2π 5π
The most kiddish yet widely used insult ever.
"lmao i fukd ur mum"
2π 6π