Demi Lovato Joined by Tove Lo for 'Cool for the Summer' Duet: Watch

Gerardo Mora/Getty Images for iHeartMedia
Demi Lovato and Tove Lo perform "Cool For The Summer" onstage during 93.3 FLZ's Jingle Ball on Dec. 19, 2015 in Tampa Bay, Fla.  

The audience at 93.3 FLZ’s Jingle Ball in Tampa were in for an unexpected treat Saturday night (Dec. 19): a Demi Lovato/Tove Lo “Cool for the Summer” duet.

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“Give it up for Tove Lo!” Lovato said as she introduced the “Talking Body” singer. Lo joined Lovato for a playful performance beginning with the song’s second verse: “Tell me if I won / If I did / What’s my prize? / I just wanna play with you, too.”

“There honestly isn't anyone cooler than @tovelo. Thanks lady for coming on stage and performing #CoolForTheSummer with me.. I'm so glad we got to know each other this tour!!” Lovato gushed alongside a picture of the pair on Instagram.

Check out their “Cool for the Summer” performance in a fan-filmed video, as well as Lovato’s Instagram post, below.