Justin Bieber Strips to His Underwear on Fashion Rocks Stage!

Justin Bieber flexes his muscles while stripping down to just his Calvin Klein boxer briefs on stage at 2014 Fashion Rocks held at the Barclays Center of Brooklyn on Tuesday (September 9) in New York City.

The 20-year-old singer was introducing Rita Ora‘s performance alongside model Lara Stone when he decided to take off all his clothes. We don’t think anyone is complaining!

PHOTOS: Check out the latest pics of Justin Bieber

“#FashionRocks,” Justin tweeted to his fans minutes before he took to the stage for the surprise appearance. Watch a short video clip below!

20+ pictures inside of Justin Bieber stripping down on stage…