Fans attending Demi Lovato's Demi World Tour in Los Angeles on Saturday night, Sept. 27, were treated to a special duet featuring Lovato and longtime friend Joe Jonas! The two performed their 2008 song 'This Is Me' from the 'Camp Rock' soundtrack.

Oh No They Didn't reports that Jonas and Lovato had not performed together since 2010. The two briefly dated that year as well.

You can hear the screams of joy coming from longtime Lovatics as Jonas makes his way on stage at the Staples Center in the fan video above.

Later that night, Jonas posted a video from rehearsals saying, "Tonight was amazing. Fun keeping this a secret."

Lovato continues on her world tour tonight, Sept. 28, in San Diego, followed by stops in Seattle, Edmonton, Calgary, Saskatoon, Sioux Falls, Moline and Chicago. She'll close out the tour on Oct. 27 in Brooklyn, New York.

Click on the video above to check out Demi and Joe back together again.

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