X Factor USA: Britney Spears covers up as Demi Lovato flashes belly

We're getting used to Britney Spears wearing low-cut tops and/or uber short hemlines at the X Factor USA auditions.

Britney Spears, Demi Lovato, X Factor USABritney Spears covered up, Demi Lovato flashed more flesh. Copyright [Rex]

So we raised an eyebrow at popstar Britney Spears' latest choice of X Factor USA auditions outfit last night.

The XF judge opted for a very demure gold long-sleeved beaded dress with a relatively conservative scalloped hemline.

Meanwhile co-panellist Demi Lovato was the one to flash the flesh - in a black cut-out mini dress that showed off her belly.

Britney Spears Demi LovatoBritney Spears and Demi Lovato posed together like BFFs. Copyright [Rex]

Singer Demi paired the sexy Topshop outfit with a shaggy multi-tone cardi and skyscraper black peep-toe heels.

She tweeted: "Loving my pink hair and obsessed with my new Topshop outfit and Chloe Green shoes!!!!"

The pair posed together at the San Francisco leg of the new series of X Factor auditions.

Britney grinned lots for the cameras, shrugging off reports that she's been a diva behind the scenes.

And the two girls, who were reported to have been at war off camera, smiled and posed with each other as if they were BFFs.

[Related story: Britney and Demi walk out of X Factor USA auditions?]

[Related story: Britney and Demi at WAR on X Factor USA?]

Simon Cowell has defended Brit, saying she is absolutely NOT too unstable to be an X Factor judge.

He said: "No she's not unstable. I'm the one that's unstable. She's working out great. All these reports that we've fallen out are nonsense. She's doing a great job."

Britney Spears, X Factor USABritney usually gets her cleavage or legs out. Copyright [Rex]

Britney Spears, X Factor USABritney got her legs out at the first X Factor USA auditions. Copyright [Rex]