Play video content EXCLUSIVE

"Twilight" actor Bronson Pelletier bitched and moaned like a schoolgirl when police cuffed him at LAX this week -- following allegations he urinated in the middle of the terminal -- and TMZ has footage of the arrest.

TMZ broke the story ... Pelletier -- who played a member of the Wolf Pack in the "Twilight" series -- was popped for public intoxication Monday, after airport employees claimed the actor drunkenly whipped out his junk in front of other passengers ... and took a whiz by his gate.

Nevertheless, the 25-year-old maintains his innocence ... insisting he's been falsely accused and no public peeing ever took place.