Watch: Britney Spears calls rude 'fan' a "f*cking a*shole"...

Opening Vegas show ended on a sour note last night (pictured)... 
According to reports, an audience member called Britney Spears a “fat b*tch.” She responded by calling them a “f*cking a*shole” during the intro of 'Till The World Ends.' Makes no sense to fork out a thousand dollars for a seat that close to the stage just to insult a pop star. Some folks have more money than sense though, and well, Britney gets the last laugh at the end of the day. Check out the moment inside.

Thoughts?