Ur sister is a mister 

An insult meaning that your sister is actually a transgender man. This insult is so rare it has only been said by 4 people and was buried in the Egyptian pyramids to never see the light of day.

Guy: ur mum gay
You take out a golden box
Guy: Holy fuck hold on man I was just joking please don’t do this
You: Ur sister is a MISTER
World explodes

Ur sister is a mister by RegimeoftheGalactic March 14, 2018

Ur sister is a mister 

An insult worse than than ur mum gay, ur dad lesbian, and ur granny tranny. This is the worst insult imaginable and there is absolutely no recovery from it.

Grant: ur mum gay
Mark: ur dad lesbian
Grant: ur granny tranny
Mark: oh yeah, well ur sister is a mister
Grant: *all veins inside body explode, has a seizure that causes him to pull out a gun from his jacket, and blow his own brains out.

Ur sister is a mister by mtersaak May 10, 2018