The Biebs danced to and lip synced the infectious tune, while Carly Rae and a crowd of 80,000 sang it at the Capital FM Summertime Ball in London!
Check out the super cute performance (above)!!
Carly Rae has a lot to thank JB for — back in February, Justin signed her to his and manager Scooter Braun’s record label, Schoolboy Records!
Not only that, but Justin's taking her on his North American tour, which kicks off this fall!
We hope Carly Rae comes out with even MORE catchy pop tracks like her hit, Call Me Maybe! Consider us obsessed!!