In fact, the pop peers hit the recording studio together to record a duet Tuesday. Bieber, 19, later posted an Instagram picture with the "Mmm Yeah" singer, 17, writing, "New music #YMCMB."
The singers also pose with Cash Money founder Birdman Young Money president Mack Maine. "What an amazing song last night," said Mahone, who is signed to Young Money Entertainment, Cash Money Records and Republic Records. "The world isn't ready!" Maine shared the same picture with his Instagram followers, adding, "Young kings in the building... @austinmahone and @justinbieber #AYC."
Mahone shared another picture with Bieber and Birdman Wednesday, writing, "Day 2! #StudioNights."
Why did Bieber and Mahone decide to team up and record a duet?
"They really respect each other's music," a source tells E! News of the heartthrobs. "They work with a lot of the same producers and Justin knew Austin has been in the studio working on his album. Justin had a song he thought could be really perfect to do with Austin so they got together in the studio."
Indeed, Mahone has been hard at work on his upcoming album, slated for release later this year.
Over the weekend, Mahone buddied up with another young pop star: Cody Simpson. Nickelodeon Kids' Choice Awards viewers were asked to vote for which singer deserved to get slimed during the show, and after the ballots were counted, both Mahone and Simpson got pummeled with green goo!