What happens in Martha's Vineyard does not always stay in Martha's Vineyard.

Sources say that some of Vice President Joe Biden's security team got engaged in a bloody barroom brawl last Thanksgiving in the Vineyard (at Nantucket's Rose & Crown Pub) -- with other members of Joe's security team.

And, the fight seems to have started because of a girl.

We heard that one of Joe's bodyguards got angry when other men assigned to Joe's security duty photographed him dancing with a female secret-service agent. Tempers flared and, well, you can just imagine what goes down when burly security guards get into a fight.

Oh, Joe. It seems like we can't always trust the people around us to behave themselves!

DiD yOu KnOw? ... This isn't the first altercation of the year involving security detail around White House members. Read all about the hooker scandal involving the secret service that happened earlier this year, right here.

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