Justin Bieber wears nothing but his wet Calvins after jumping into a glacial lake in Iceland

Justin Bieber is really taking his role as the face and body of Calvin Klein to a new extreme wearing nothing but his tightly whitey's to plunge into icy water in Iceland on Tuesday September 23.

The 21-year-old "What Do You Mean?" entertainer flaunts his many tattoos and muscular mid-section, not to mention his nearly see-through undies!