Britney Spears and Demi Lovato Cut LooseGlamour shots! Terrorizing Simon Cowell! The judges share personal pics from backstage at X Factor and more

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LASTING IMPRESSION

"XFACTOR TONIGHT!!!!!!!!" Tweeted an excited Lovato alongside a shot from the show's premiere, where the judges left their handprints in the cement outside L.A.'s famed Grauman's Chinese Theatre.