Demi Lovato: iHeartRadio Music Festival Presenter

Demi Lovato, in TopShop, snaps a pic with Ryan Seacrest backstage before an interview at the 2012 iHeartRadio Music Festival at the MGM Grand Garden Arena on Friday (September 21) in Las Vegas.

The 20-year-old X Factor judge, alongside Mario Lopez, introduced Green Day to the stage.

PHOTOS: Check out the latest pics of Demi Lovato

“Oh haaaaayyyyyy Vegas!!!” Demi tweeted earlier in the day.

Demi recently appeared on Katie Couric‘s new talk show Katie, where she talked about her time in a treatment facility.

The episode will air Monday, September 24th. Check your local listings for time and channel!