Like a tattooed lamb to the slaughter, Justin Bieber has agreed to be the guest of honor at a Comedy Central Roast in March … and you can already hear Jeff Ross licking his chops. As for roast topics, it’s not like there’s a shortage of material, for example: — Pissing in mop buckets — Egging houses — Lambo arrest — Fighting Orlando Bloom — Dropping the N-word — Calvin Klein modeling shots — Anne Frank shout-outs — Push-ups in jail — Fighting with Keyshawn Johnson — Fear of shirts … and oh yeah, his music career. Word on the street is that Bieber was game to be roasted for a while … and had been hoping to work out a deal with the network.