Here's a painful lesson on why you should NEVER get in a street fight -- courtesy of UFC star "Platinum" Mike Perry.
We asked Platinum -- who fights this weekend at UFC on FOX 26 -- to give us the lowdown on if he's ever had to throw down outside the Octagon ... and the story he hit us with was Oscar-worthy.
It all went down on a New Year's Eve in DT Orlando ... when Mike and his GF, "Platinum Princess" Danielle Nickerson, were out celebrating on the streets.
Perry says a random guy was dumb enough to hit on Danielle when they were clearly together .