Here in the U.S. we know Katy Perry as that “I Kissed a Girl” girl and Lily Allen as that British Britney-Spears-esque mess. But across the pond, they are bona fide pop stars who really don’t like each other.
 

The latest battle began when Perry referred to herself as “a skinnier version of Lily Allen.” You don’t call Lils fat and get away with it. Allen shot back, calling Katy “crass.”

Now the feud’s heading to Facebook.
 

Allen brought her anger to her Facebook page, writing “I have Katy Perry’s number, someone did me a favor. I’m just waiting for her to open her mouth one more time then it hits Facebook.” Yes, she went there.
 

But actions speak louder than words and Allen took action joining two choice Facebook groups: “I hate Katy Perry and her dumb-ass song I Kissed A Girl” and “Katy Perry? Who in the hell does she think she is?”
 

Facebook burn!