Justin Bieber's entourage and security at the BET Awards got into a heated showdown -- which ended with JB declaring the doorman was "a douche bag" ... and the whole incident went down on camera.
TMZ obtained the video, which shows Bieber -- who was a presenter at the award show -- and his squad being stopped at the door last weekend. It appears one of Justin's bodyguards did NOT have a ticket ... and while both sides argued, Biebs eventually interrupted by saying, "I need to bring my security! This guy's a douche bag."
Everyone on Team Bieb ended up getting into the show -- and a BET rep downplayed the incident ... saying, "It is our standard policy to make sure everyone has their tickets or credential upon arrival. Justin had the proper credentials."
As for Justin -- his rep says the Biebs was just standing up for his bodyguards ... the guys who always have his back.