your mum

its a joke thats funny because of joe biden

(your mum) is a dirty slag

Your mum

defining something big and fat
sometimes hot

Greefy: he look at that big plane over there. I wonder whats the dimensions of it
Beefy: I am very sure thats around the size of that of your mum.

Your mum is ugly

Sup bro

Your mum is ugly

flair your mum

Bending your mother to look like a scooter then perform a flair

I am going to flair your mum

Marshmallow your mum

A disgusting sex act.

Phil Lester: "I'll marshmallow your mum"

your mum i have fucked

lmao it might be true

i fucked your mum tyson, your mum i have fucked

What's your mum?

Used as a comeback when someone insults you,
or just when someone says anything really..

Fred: OMG, you're such a gimp.
Bill: What's your mum?

Luke: This milk has gone off. It's all stale and lumpy.
Jane: What's your mum?

Etc.