Justin Bieber, 20, just upped the hotness bigtime at Fashion Rocks. He came out to introduce a stellar performance by Rita Ora with model Lara Stone — but totally stole the show! We loved the blue blazer he was rocking, but he didn’t keep it on long. Instead, he actually threw it on the floor, with the rest of his clothes. Yes, he stripped down to his Calvin Klein undies!
SEXYeS or SEXYNot?