Queen Elizabeth's Guard -- Tongues Tourists on Camera!! (VIDEO)

Here's something to get Queen Elizabeth's britches in a bunch -- video of one of her famous Royal Foot Guards slacking on the job, but in a pretty funny way.

The radical break with royal tradition went down at Buckingham Palace ... where the guard in question decided to put on a show for tourists -- cracking smiles, making faces, and sticking out his tongue.

QE2's protectors usually stand stoned face and never react to anything.