Justin Bieber has been spotted wearing even fewer clothes than usual. Photographs have been leaked online which show the pop sensation naked, using his guitar to cover his manhood. It seems as a Thanksgiving prank Bieber sang naked to his grandmother.

Justin Bieber
Justin Bieber performing in Tampa, Florida.

So, why did Justin Bieber serenade his grandma naked?

We really don't know. The obtained TMZ photographs show the 19 year old singer letting it all hang out whilst visiting his Grandmother's Toronto home last year.

The two obtained photographs show Bieber's thanksgiving antics. In one, Bieber smiles into the camera covering his Fans are in luck with the next photograph which shows the rear view, including Bieber's own rear end, where Bieber is singing to his grandmother whilst she looks perplexed. 

At Thanksgiving, it appears Bieber decided to amuse his grandmother and other family members by appearing naked, protecting his modesty with a guitar. 

Justin Bieber
Justin Bieber performing at the MGM Grand Garden Arena in Las Vegas.

According to sources speaking to the entertainment website, Bieber woke late on Thanksgiving morning and appeared, with nothing but his guitar. He then wandered directly up to his grandmother and sang "I love you grandma/How are you?/Hello grandma."

Apparently, Grandma found the whole prank high amusing, but begged her grandson but dress. 

Whether or not she finds Bieber's other antics as amusing is another matter. Most recently Bieber has been indulging in urinating in public; swearing at pictures of Bill Clinton and spitting from balconies. His latest misbehaviour occurred on 4th August when the 'Baby' singer and his entourage were allegedly involved in a club fight in a nightclub in Southampton, New York.

Justin Bieber
Justin Bieber at 40th Anniversary of the American Music Awards, held at the Nokia Theatre in L.A.