Justin Bieber Naked Just To Prank Mum And Family (Photos)

Wow! It seems what many people may have been secretly waiting for is now here. Justin Bierber Naked! But the good news for all Justin Bierber fans is that, the music superstar was not in a porn movie or caught having sex but he did it just to strengthen some family ties.

The pictures and story was made public by TMZ.

But why will Justin go naked for granma and family?

According to TMZ 'Our sources tell us JB had been staying at his granny's house during the holiday ... and slept in a little too late on Thanksgiving morning. 

Bieber finally woke up after hearing family and friends stirring around the house -- so he thought he'd prank 'em ... by grabbing his guitar and playing a naked set a la Jenny from "Forrest Gump" ('memba that?).

We're told birthday-suited Bieber went right up to his grandma and started belting out some impromptu lyrics ... like, "I Loooove you grandmaaaa ... how are youuuu ... helloooo grandma."

We're told G thought it was pretty funny -- and everyone in the home was cracking up -- but granny begged the pop star to get back in his room to put some damn clothes on, stat.'

TMZ