Mate... what?
A way of showing how something is annoying you.
Mate... what? Said Hood Stinky as he got killed by King K. Rool in Super Smash Bros. Ultimate.
What Mate!!!
uSED IN ANGER WHEN SICK OF HEARING A dOHRMANN ASK YOU INSESENT QUESTIONS, OR PRANKING YOU AT 3AM WHEN YOU LIVE IN CANADA
(phone rings) (6am canadian time, midnight Australia)
Fuckin' WHAT MATE
Fuckin' WHAT MATE
I'll tell you what mate
The last thing you hear before being stabbed in the chest by a 10 cm long knife in north London. Could also be in Birmingham or Glasgow. Whatever you do if you hear this sentence run away.
Bruh, I'll tell you what mate