Singer Justin Bieber and Floyd Mayweather Jr. pose after Mayweather Jr. defeats Miguel Cotto. Photo / Getty
Justin Bieber and Floyd Mayweather have had a huge falling out, with the pop star reportedly "distancing" himself from the boxer.
Sources told TMZ Bieber was reassessing his friendships and wanted to "reset boundaries" with Mayweather.
And the boxer did not take it well, going "insane, nuclear" and calling Biebs a "traitor."
The Despacito singer unfollowed Mayweather on Instagram, a move that has left Mayweather incensed ahead of his fight against Conor McGregor in Las Vegas this weekend.
TMZ says Bieber's Hillsong Church friends have been "counselling" him to distance himself from the "bad influences" in his life.
Mayweather has a long history of hard partying, including at strip clubs.
But sources reckon Bieber didn't want to cut Mayweather off entirely - he just wanted some space.
New York Post reports that Bieber and Mayweather were once close, with Bieber accompanying Mayweather in his ring walk to some of his biggest fights, and have taken holidays together.
The Australian site cited a 'heightened threat level' as the issue.