Joe Jonas and Demi Lovato Surprise Fans With Their 'Camp Rock' Duet 'Gotta Find You' at Her Washington, D.C. Concert

So sweet! Joe Jonas and Demi Lovato are proof exes can definitely stay friends.

The DNCE frontman made a surprise appearance at Lovato and brother Nick’s Washington. D.C. show Tuesday night.

“Sharing the stage with @nickjonas and @ddlovato in DC last night!” Jonas – whose band is also currently touring with Selena Gomez – captioned a photo of him and Lovato hugging onstage.

He continued: “Surprising Demi with Gotta find you was something I will never forget! Thanks for having me guys! Amazing show you two put on. Proud to have such talented wonderful people in my life.”

Jonas, 26, and Lovato, 23, first met on the set of Camp Rock in 2007 and went public with their relationship in March 2010. The pair called it quits just two months later, but have maintained their friendship over the years.

“Demi and I knew going into our romantic relationship that it may not be an easy one,” Jonas told PEOPLE at the time.

He added: “I realize over the time we have shared together that I feel I care more about our friendship right now. It was my choice to break up but I love her as a friend. She’s been there for me when I needed her. I will continue to be her friend and be there for her.”

Both singers are currently single. In June, Lovato and her longtime boyfriend Wilmer Valderrama revealed they had broken up after six years together, but she’s been having fun getting back into the dating scene.

A source recently told PEOPLE the “Confident” singer had a “quick fling” with MMA pro fighter Guilherme “Bomba” Vansconcelos, and she was also spotted on a dinner date with Odell Beckham Jr. earlier this month.

Meanwhile, Jonas and model girlfriend Gigi Hadid split last November.