This is what happens if you heckle Britney Spears at a gig and she hears you: you'll be called a 'f**king asshole".

In this particular case, however, Ms. Spears was right on the money. During her gig in Las Vegas the other night - where she is currently undertaking a residency - some rude person called the pop star a "fat b*tch", according to TMZ.

Unfortunately for him, Spears heard him and proceeded to call him out for the 'f**king asshole' that he is. 

Watch the video below: