Justin Bieber 'Pranks' His Grandma with a Sexy Nude Serenade [NSFW]

Justin Bieber has something of a knack for rubbing objects on his junk.

But he apparently went whole-hog last Canadian Thanksgiving while visiting his grandma in Tornoto.

According to TMZ, Bieber had overslept that October morning, and awoke to his family noisily gathering downstairs.

So, being the Bieber we all know and tolerate, he decided to play one of his classic pranks and show up to the reunion in his birthday suit with only a guitar between him and indecent exposure.

TMZ, which obtained photos of Bieber's buck-naked serenade, says the 19-year-old man-child was strumming along to nothing in particular while singing "I love you grandma."

Bieber's nana, for her part, thought her grandson's semi-incestuous shenanigans were a hoot, but asked him to put his clothes back on just the same.

Justin Bieber 'Pranks' His Grandma with a Sexy Nude Serenade [NSFW]

Justin Bieber 'Pranks' His Grandma with a Sexy Nude Serenade [NSFW]

[photos via TMZ]