justin bieber is showing his ass!
in more ways than one.
he decided to serenade his grandmuvvah nekkid one morning last year.
i know what you’re thinking.
“um ew”.
well there is a logical explanation i’m sure for this lovely gesture…

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.

well…
that was…
uh…
interesting.
i wonder what he did for christmas?

source for this wonderful story: tmz