Justin Bieber and Floyd Mayweather perform karaoke while on holiday in Bora Bora

Bieber performs one of his own songs, which seems a bit unusual

(Instagram)

There’s nothing quite like having the brass to sing your song own song at karaoke, but, if you’re a certain Justin Bieber, and you’re responsible for the quite-good song 'What Do You Mean', then you can probably do whatever you want.

Bieber was taking a break from his stressful career as a young multi-millionaire by vacationing in Bora Bora with retired boxer Floyd Mayweather when he took to the mic and performed one of his own songs, with footage finding its way to TMZ.

He also sang some of the Beatles for the oldies in the crowd who don’t know much about modern pop music. What a crowd pleaser.

He’s accompanied by none other than Mayweather, who owns a holiday home on the island and can therefore be expected to have similar levels of stress to poor overworked Bieber.

While Mayweather doesn’t do a great deal of singing in the clip, he proves his worth with a bit of dad-dancing in the background and even manages a few claps, although they're a bit out of time.

But what do 19-year-old Bieber and 38-year-old Mayweather have in common?

What do they talk about?

Sadly we don’t know at this point, but the hashtags #bankrollbieber #gettinmoney and #paycation all suggest Mayweather has come into a bit of money recently. Anyone?