CelebSpice

Pop star and American idol guest judge Katy Perry did her best at being a catty talent show judge and matched wits with Kara Dioguardi during the auditions for season nine in Los Angeles.

The show airs each week on fox and during the auditions on the west coast, the two female judges clashed.
Pop Crunch notes: "The girls disagreed over several of the contestants during the L.A. auditions, but things really got ugly when Kara began mocking Katy's breakout hit I Kissed A Girl," the report notes.  

They have video here. The singer also said she loves idol and wouldn't mind being a full-time judge. Could Kara and Katy take the catty act to the airwaves after Simon Cowell leaves the show?  
Perry has said she would give up her singing career if she was given a permanent judging role on American Idol. The 25-year-old recently made an appearance on the show as a guest judge and said she had a great time.

She said to MTV News: "I make 'em cry all the time. The American Idol experience was awesome. If I was offered that job as a permanent host, I would ditch my career and take on that career."
Perry added: "American Idol was great fun. It was so easy. I didn't really make anybody cry, but I did tell the truth to some kids that might have needed to hear it."