Demi Lovato is pretty hilarious with Simon Cowell and Co. on 'X Factor,' and she got even sillier last night on 'Jimmy Kimmel Live.'

Sporting a short A-line printed dress and black leather motorcycle jacket, Demi looked more like Taylor Momsen than herself, accessorizing with heavy black eyeliner and light blonde bangs. She revealed exactly how her 'X Factor' judging position came about: She didn't chase them, they sought her out. Specifically Simon, who, based on their banter every week, may regret that decision.

"He kinda just called me up one day," she laughed. I was like, "I don't know, I'm really busy for your little show," she said with extreme hyperbole. "Britney who? And then they begged me, so ... " Demi revealed she didn't have any screen tests, but that she had met Cowell before. "I met him on 'American Idol' a few times and he didn't remember me," she chuckled. "He knows what he's doing. He's really smart and I hate him!"

Demz also revealed that she and Cowell actually get along really well off camera and that switching seats with Spears was likely to make her stop having to lean over to yell at Simon.

Then Kimmel brought out the big question: "If Simon were 25 years old, would you date him?"

"No!" Demi exclaimed, before explaining, "He parts his hair down the middle!" She also revealed how he gets his coif just so perfect -- and how she and her colleagues deal with boos from the crowd, competition from 'American Idol' and what happens when girls throw underwear at her onstage!

Watch Demi Lovato on 'Jimmy Kimmel Live' Part 2