16 Photos You Need to See from the iHeartRadio Festival

What happened in Vegas this weekend didn't stay there! See how Taylor, Ariana, Alicia, Usher and more celebrated in Sin City

PEACE OUT

Sporting cute cat ears and a sparkly frock, Ariana Grande puckers up backstage at the 2014 iHeartRadio Music Festival at the MGM Grand Garden Arena on Friday night before taking the stage to perform.