Justin Bieber Has A New Model All Over His Junk -- Comedy Central Roastmaster Jeffrey Ross! See The Biebs Get Totally Creeped Out HERE!

Justin Bieber may have bitten off more than he could chew when he agreed to be the victim guest at a Comedy Central Roast on March 30th.
A LOT more.
This latest spot for the upcoming event mimics the Biebs’ Calvin Klein campaign.
[ Photos: Justin Bieber Parties With A Hot Model For His 21st Birthday! ]
Only instead of supermodel Lara Stone, Justin has to cuddle with Roastmaster Jeffrey Ross!
See Justin get VERY uncomfortable with the insult comic’s improvisations (below)!