Justin Bieber Strips Down for Calvin Klein Underwear Campaign

Justin Bieber is all grown up and showing off. The pop heartthrob flaunts his physique as part of Calvin Klein’s underwear campaign.

In one of the sexy photos, the 20-year-old singer bares his tatted chest while standing in his boxer briefs.

“This is just the start of the year #mycalvins #beallyoucanbe #learnfromyourfaults #risetosuccess #dontbeashamedredeem #thebestisyet2come,” said Bieber.

A half-naked Bieber gets intimate with model Lara Stone in another black-and-white ad for Calvin Klein Jeans, and plays the drums shirtless in a video clip.

Justin Bieber and Lara Stone

The steamy pics nearly sent his Beliebers into cardiac arrest. See one over-the-top reaction below.

Last September, Bieber gave his fans a peek when he stripped down to his Calvins while presenting at Fashion Rocks 2014.