Justin Bieber put on his boxing gloves for a training session with Floyd Mayweather on Thursday night! The pop star and the boxing champ entered the ring at the Ten Goose Boxing Gym in Van Nuys, Calif.
The fellas documented the whole night, sharing videos and photos on Instagram, Vine, and Shots.
The Biebs even called Mayweather his trainer in one pic. In turn, the boxer crafted a new nickname for Justin, calling him -- "Moneybags."
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Bieber, 20, struck up a friendship with Mayweather, 37, back in 2012. The "Boyfriend" singer has been known to escort the fighter into the ring before fights. In May, Justin walked Floyd into the arena before the WBC/WBA Welterweight Unification Fight in Las Vegas, Nev.
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Bieber was also spotted at a match last month -- even bringing along his on-again/off-again girlfriend, Selena Gomez, to watch the action in Las Vegas.
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Floyd's 14-year-old daughter, Iyanna Mayweather, also has a reportedly long-standing crush on the swaggy star. How cute!
What do you think of Bieber and Mayweather's boxing sessions? Will JB ever get in the ring and fight someone for real? Or, is this just a fun hobby for him? Let us know in the comments section or we can chat on Twitter using the hashtag #ETNow.