A phrase used to put pressure on the person who is about to focus or carry out an important action, in 90% of cases resulting in the person performing an epic fail.

The term is so useful as there is not a single person on the planet that will not get intimidated by a mother's look of disapproval and even a thought about your mother watching you fail makes you nervous as hell, so you will almost certainly cock up whatever important thing you are doing.

Your mum in the ultimate come back for anything that anyone says. It originated back in the 2000's when teenagers found that answering questions was just plain boring, so instead, 'You Mum/Mom' became the lazy excuse for everything.

a "your mum" joke lasting for at least a minute complex enough to involve a cast of people and a plot. Usually involving your mother being violated, raped, whoring herself out for money or undergoing some form of gender reassingment. Consistently racist with massive stereotyping. Some your mum epics are long enough to have recurring themes or subplots.

This is one of the only true comebacks to a your mum joke.
However the story must remain clear enough to be understood but grotesque and violent enough to prevent any interruptions. delivery must be deadpan but speedy.

Do not attempt this if you do not have an extremely sick mind or cannot think on your feet as a timid ending can make you look like a complete arsehole.

it is used by townies/chavs.

To shove a large, vainy, hard, wet, dick up someone’s mum making her scream at the top of her lungs ‘I’m going to cum!!’

Basically meaning get to fuck.
A retaliation to being slagged off. Insults a person if they are being dickish. There is no comeback to that.

Used when decsribing another's mother's mammary glands. Or cancers thereof. It is what it is. Briem.