Demi Lovato branded ‘brat’ by Cowell

Demi Lovato was jokingly called an "obnoxious brat" by Simon Cowell at last night's Teen Choice Awards.

The former Disney star was hosting the annual ceremony alongside Glee star Kevin McHale.

Demi, 19, is currently a judge on the US version of The X Factor alongside Simon and he recorded a video message for her which was played as proceedings kicked off at Universal City's Gibson Amphitheatre.

"[She is] annoying, obnoxious, disruptive, gobby, irritating, bad manners, not great taste — did I say irritating? Yes? Annoying, very annoying. She's a brat. Um, I could go on for hours, but that's what makes her special, and I really do love her, a bit. Have a great night, wish I was there, but no one invited me," Simon laughed.

Demi didn't take the comment lying down, hinting Simon has had a difficult time dealing with her opinions on the programme.

"He's just old. He isn't used to women in this century being able to say what they want," she joked.

Britney Spears and L.A. Reid are also on the judging panel and sent Demi words of encouragement.

Demi picked up prizes for the best summer music star and best Twitter star, with Britney quick to congratulate her.

"Congrats on your wins at the Teen Choice Awards tonight @ddlovato! Let's celebrate when you get to Miami :) (sic)," she wrote on Twitter.

Demi gave the presenting job her all, smiling throughout and even showing off her tattoos at one point. Her multiple wardrobe changes went down a storm with the crowd, especially the armour-inspired dress she wore on the pink carpet.

The star's friend and fellow former Disney star Selena Gomez also had a good night. She turned 20 yesterday, with the entire audience bursting into a rendition of Happy Birthday to help her celebrate. She was presented with a cake when she took to the stage and also picked up the best group prize for her band Selena Gomez & The Scene.