Justin Bieber reportedly serenaded his grandmother in the nude.
Newly revealed images show the 19-year-old completely naked apart from a guitar covering his private parts on the doorstep of Diane Dale's home.
According to TMZ the incident took place at Justin's grandmother's home in Toronto during Canadian Thanksgiving in October 2012.
Sources told the website that Justin had been staying at Diane's home during the holiday.
The teen heartthrob is said to have slept in late on Thanksgiving morning, missing the rest of the family's arrivals for the celebration.
When Justin woke up, he allegedly decided to prank the family by grabbing his guitar and playing a naked set.
The website reports it was his grandma who was the first to come face-to-face with Justin in his birthday suit. The pop star went straight up to her and began belting out spontaneous lyrics, which his good natured grandparent is said to have enjoyed.
TMZ added that Diane found the prank hilarious, as did the rest of the assembled Bieber clan.
Once laughter had died down, Justin was ordered by Diane to return to his room immediately to put on some clothes.
Diane is the mother of Justin's mom Pattie Mallette and she helped raise the singer.
In July, Diane gave an interview about her grandson's controversial behaviour, which has included peeing in buckets and apparently spitting on innocent bystanders.
Diane defended her grandson against the criticism he received, telling Ottawa’s CTV that Justin's antics are completely normal.
“It’s totally crazy,” Diane insisted according to RadarOnline. “I feel sorry for Justin all the time, because paparazzi pick on him all the time. Anybody else’s kids have done the same thing but nobody says anything. He’s a 19-year-old boy. And before you criticise him, say, ‘What is my 19-year-old boy doing?’”
Justin's popularity was apparent at last night's Teen Choice Awards, where he scooped the choice male artist award and took the crown for the hottest Twitter personality for his social networking updates.
"4 years in a row. #tcas. That's love. Thank u. Enjoying the break. But always here. Thank u. This is forever :)," Justin tweeted. "Our story. Our awards. Our songs. Our albums. Our tour. Our journey...just beginning. This is forever. Thank u. Love (sic)."