Definitions by M.B.F.

FTSU 

Fuck that! Shut Up!!! or
Fuck The Shut Up, like the bedt response back to someone said STFU to you!

friend A: U better STFU, u mofo!
friend B: FTSU! im gonna tell, im gonna make sure everyone one in the world know about what you did to friend C, just wait for it!

FTSU by M.B.F. February 7, 2024