An absolutely diabolical insult, extremely similar to "Your Mum gay, your daddy lesbian, and other such". This is an insult on a scale with power similiar to that of God himself, so, unless you want the universe to crumble before you, do not use this terrfiying phrase.
Carl: Your Mum Gay!
Dylan:Your sister a mister!
*The Earth begins to shake as Carl readies the blow to Dylan"

Carl:Your brother your-
Dylan:DON'T SAY IT CARL!
Carl: I must.... YOUR BROTHER YOUR MOTHER!

*Cries are heard from across the universe as, atom by atom, molecule by molecule, the universe begins to crumble away, for not even God can save us now*
by Gabe_TryToFindMeNow March 18, 2018
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this is legit deadass the worstest insult you can use on someone,worse than your mom gay, your dad lesbian and your granny a tranny say it out loud and every nigga within a 17 feet radius just dies as they hate their brother being their mother
by Big_nigga103 March 17, 2018
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Possibly the most dangerous phrase since humans have developed vocal cords, above “your sister a mister” and “ your granny tranny”. Every time this is said the universe speeds up, the sun expands and god himself worries for his future
person 1 your mum gay
person 2 your dad lesbian
person 1 your granny tranny
person 2 your sister a mister
Person 1 your brother your mother
god *cries*
by @matwai_ on ig March 16, 2018
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The worst of the worst of insults. The only thing that stumps this is Your grandpap a trap. Its some heavy shit though.
Me: Your mom gay
Friend: No U
Me: Your brother a mother
Everyone implodes
by Double.xd March 22, 2018
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A counter to the recently discovered "ur sister a mister". Grants immunity to any "no u"
(Mohammed is getting a bit cheecky)
"Your brother a mother"
(S.A.S arrive at your door and kill you because you are too much of a threat to mankind)
by Yoot March 18, 2018
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The Worst of the Worst of the family phrases! Never to be used lightly!
Your Brother A Mother Gavin!
by Handle Jangle March 20, 2018
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This is the GOD TIER of comebacks. Worse than “Your mom gay”, “Your dad lesbian”, Your granny tranny”, and “Your sister a mister”. No escaping, or deflecting this. You are all doomed...
Ricky: “Your mom gay”
John: “Your dad lesbian
Brittney: “Your granny tranny”
Jake: “Your sister a mister
Me: “Your brother a mother
*Everyone dies*
by Ephexia March 22, 2018
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