This just in from the strange planet of teen star Justin Bieber: photos have emerged of the star online pictured after he turned up on his grandparents doorstep starkers with just an acoustic guitar to cover what is left of his modesty. Think of all those girls who've laid claim to the so-called heartthrob and who've had tirades launched against them by a jealous storm of Beliebers. Well that exclusive list of ladies who've clapped eyes on Beiber in the buff has just gained another, rather aged member.

Justin Bieber
Baby, Baby, Baby, NO!

Obtained by TMZ, the photos were taken last October - as evidenced by the 'Baby singer's barely tattooed body - and depicted the moment that lil Biebs debuted an exclusive new song for his Grandma's ears only. The 19 year-old showed off his "famed" songwriting skills strumming away whilst warbling a very special serenade: "I love you grandma, how are you, hello grandma."

Justin Bieber
Biebs Cops A Feel Of Himself To Check Whether Anything's Happening Down There Yet.

The pics show the slightly frightened look from his granny Diane as the knock at her door turned out to be a strippergram that was a little too close to home. The intimate and (hopefully) one-off performance came on Thanksgiving last year whilst Bieber had been staying with his grandparents. As the first to rise, he thought he'd play a very unique prank on his unsuspecting family to make sure it was a holiday they'd never forget.

Justin Bieber
Wanna Know What Justin Looks Like Naked? Neither Did We But It's Too Late Now.

TMZ's sources say that, however creepy, the prank was well-received with everyone cracking up and admiring the talent and wit of their famous relative as he sang and played guitar in the nudie-rudie like some kind of stripper-cum-minstrel. Though apparently after he'd had his fun, Diane demanded that he go away and put some clothes on.

Justin Bieber
Is He Thinking About His Nan Here?

The (quite literally) balls out prank from our favourite scamp isn't a world away from his usual appearance. Bieber is known to triumph the "pants-hanging-below-the-butt" look, which frankly should have died in the 90s. His jeans usually sit south of that sacred zone known as the buttocks, perhaps to facilitate ease of removal should he have to dash to the toilet or, as recently demonstrated, the cleaner's mop bucket.

Justin Bieber
Oops! Looks Like It's Time For One Of Those Urgent Toilet Dashes: Good Job His Pants Are Low.

Performing at the weekend at a Jacksonville, Florida concert, the rebellious popstar almost lost his trousers completely on stage mid-performance of his hit 'Baby.' His trousers slid down his legs and almost hit the floor as Biebs tried to style it out and not act like he was about to go in the scuds.

For the boy who isn't legally allowed to drink yet, he's developed a mating technique not unlike the anglerfish's lure. Sources say he uses a flashlight to examine and pick out the girls he's interested in in a crowd. Flashlight stays on you: you're next.

Justin Bieber
He Probably Debuted This Dance Move For His Grandma.

Where Bieber's concerned there's been far too much "flashing" of late: put it away dude!