Selena Gomez Bares Midriff Backstage at Z100's Jingle Ball!

Selena Gomez and Robin Thicke are all smiles while posing backstage at Z100′s Jingle Ball 2013 held at Madison Square Garden on Friday (December 13) in New York City.

On the same day, the 21-year-old entertainer was spotted showing off her midriff in a purple top during an interview backstage.

PHOTOS: Check out the latest pics of Selena Gomez

Later in the day, Selena was introduced by Katie Holmes before taking the stage to wow the crowd.

Over the weekend, Selena performed at the 2013 106.1 KISS FM Jingle Ball held at Comcast Arena in Seattle, Wash.

20+ pictures inside of Selena Gomez attending Z100′s Jingle Ball…