'Twilight' Actor Bronson Pelletier -- I'm NO Airport Urinator!

Bronson Pelletier -- who played a member of the Wolf Pack in the "Twilight" saga -- tells TMZ he's been FALSELY accused of drunkenly peeing in public at an airport terminal ... and insists he's the victim of a sick and twisted setup.

We broke the story ... Pelletier was removed from an airplane and arrested at LAX this week for public intoxication ... and was allegedly so drunk, he urinated in public near the gate.

But yesterday in L.A., the 25-year-old actor was in hardcore denial mode -- telling TMZ, "No peeing ... peeing did not happen."

So what DID happen? Pelletier says he was set up ... claiming "some guy" had been buying him drinks at the airport before he got on the plane ... and the "same guy" later had him removed from his plane.

Pelletier's camp believes the guy who bought the actor the drinks is an obsessed fan.

We also asked Pelletier about a prior arrest for felony cocaine and meth possession -- but Bronson denied that too ... saying, "That situation was ... uh, yeah, no ... that did not happen."