File this one under "duh."

According to TMZ, 'Jersey Shore' stars Mike "The Situation" Sorrentino and Ronnie Ortiz-Magro got into a "major fist fight" while filming Tuesday night in Florence, Italy.

Nobody knows yet why the fight broke out, though sources for TMZ claim the brawl possibly started "after a blowout" between Ronnie and his on-again, off-again girlfriend, Sammi.

TMZ also posted photos from the aftermath, which show Ronnie's knuckles and The Situation's face badly cut up.

Given the show's history with fights, we can't say we're all that surprised.

[TMZ]