Justin Bieber is expanding his horizons lately, boxing with Mike Tyson, the former undisputed heavyweight champion of the world.

Teenage heartthrob Bieber, 18, may have developed a love of boxing. He was spotted buddying up to Floyd Mayweather after his Las Vegas victory last month, and now he's taking lessons from Tyson, 45, who once bit off Evander Holyfield's ear in the ring.

Tyson took to Twitter, Instagram, and YouTube to post images and video of himself with "Boyfriend" singer Bieber and John Shahidi. "Me, @john and @justinbieber before we started training JB," Tyson tweeted, showing the three new buds in the gym.

"Justin swung by my place during the weekend of the Billboard music Awards to say hi to the family," Tyson wrote about Bieber, who also spent some time horsing around with Tyson's seven kids — according to Us Weeklyon his YouTube page. "We took him straight to garage and had him hit the bags. JB's got the moves!" Tyson wrote.

In addition to toning up with sports legends, Bieber also recently revealed that he was teaming up again with Ludacris, 34, following 2010's "Baby," for their new "All Around the World" single, a pop / hip-hop hybrid off of Bieber's Believe album. The chorus spreads the message of world peace: "All around the world / People want to be loved, yeah / 'Cause all around the world / They're no different from us." Take a listen below.

Check out Justin Bieber's new "All Around the World" single, featuring Ludacris:

Watch Justin Bieber train with Mike Tyson:

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