Warren Sapp -- Is Not Happy Right Now

Yeah ... that $100,000 bet was a bad idea.

Really bad.

We broke the story ... Sapp -- who filed for bankruptcy back in 2012 -- made a $100k Super Bowl bet with rap mogul Rick Ross. The bet was captured on video ... so it's gonna be hard for Sapp to back out.

Sapp took the Broncos. Ross took the Seahawks.

Sapp lost.

Warren's gonna have to find a way to come up with $100k, stat ... 'cause Rick doesn't seem like the kinda guy you wanna owe money to.

Just sayin' ...