Simon Cowell has been making the promo rounds, flanked by his 'X Factor' girls, on an assortment of TV programs. Last night (Sept. 17), when accompanied by newbie judge Demi Lovato on the 'Conan' show, he got more than he bargained for and was subjected to more abuse from his sidekick. She called him an "a--hole" on national late night TV. Go get 'em, Deemz!

Looking fierce in a lime green flowered dress with statement shoulders, the fiesty 'Give Your Heart a Break' singer said the acid-tongued Cowell shows more cleavage than she and Britney Spears do, thanks to his extra-tight tees.

Conan egged on their banter, reminding them that Cowell has repeatedly stated that he finds Lovato to be annoying in the press. He didn't backpedal, declaring, "You are very annoying. How is that? Well you are."

"How's that?" Lovato responded. "You can be a bit of an a--hole." Game, set, match to Lovato!

While we think that the back and forth between Cowell and Lovato is entertaining, we are beginning to wonder if it's scripted or embellished. What do you think, PopCrushers? Are these two mugging for the cameras or is there a genuine love-hate relationship in place?

If you wanna see more of their back and forth, tune into 'X Factor' tomorrow (Sept. 19) at 8PM ET on FOX.

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