Movie star GEORGE CLOONEY has threatened to 'murder' BRAD PITT if he steals the limelight in their new film BURN AFTER READING. The pair have appeared together before - most recently in 2007's Ocean's 13 - but Clooney is worried his performance will be overshadowed by that of the blonde Mr + Mrs Smith star. He says, "I'm working with him right now on this Coen brothers movie, which kills me because he's going to steal the movie and I'm going to murder him." But Clooney insists it's not just Pitt who he worries about - adding he'd love to "kick Matt Damon's ass." He explains, "It's a weird thing, but you try not to compete in art. It always seems kind of strange. I could never do the things that he (Pitt) does, ever. I do have some competition with Matt Damon - I'd like to kick his ass," Clooney smiled.