(Cover) - EN Showbiz - Demi Lovato sometimes asks Britney Spears "what she was thinking" when she puts certain acts through on The X Factor US.

The two singers star as judges on the hit TV talent show, alongside Simon Cowell and L.A. Reid. Demi has revealed who she tends to agree with most on the panel.

"It's unpredictable. Like sometimes I cannot see what Simon sees in the people he puts through. And same with Britney," she explained to MTV News. "I'm like, 'Britney, what are you thinking?'

"But there are more times I relate with Britney [better] than Simon, actually. Maybe because we're the two girls on the show."

Demi likes to give constructive criticism to hopefuls who appear on the show. The 19-year-old star doesn't hold back when it comes to giving her opinion.

"I'm really honest on the show and sometimes I come off as the toughest judge. I guess you can say I speak my mind," she smiled. (C) Cover Media