"Heartbreaker" singer Justin Bieber's latest controversy is very eye-catching. Selena Gomez' ex-boyfriend and Instagram video lover posed naked with guitar covering his private parts in newly surfaced viral photos.

According to TMZ, the baby-faced crooner, 19, stripped off his clothing to do a nude serenade for a lucky fan in October 2012. 

[For the censored photos, click HERE.]

The fan just so happened to be his grandmother, who the singer performed for in his naked glory during a Canadian Thanksgiving at her home in Toronto, reported the celebrity news site.

But why would the singer bare it all during a family holiday?

Bieber, who had slept in late that day, heard his family celebrating and wanted to play a prank on them. His idea of a joke was grabbing a guitar and going completely buff, according to TMZ.

The "Never Say Never" performer went up to his grandmother, singing "I Love You Grandmaaaaa...How are youuuu...helloooo grandma" while in his birthday suit. 

Apparently, Bieber's family thought the joke was funny. But his grandmother begged him to go back in his room and put some clothes on before he scared anyone.

Think Bieber's was amusing or downright inappropriate with the prank? Tell us in the comments section below!