Riteish Deshmukh is working on building more muscle to flaunt in Housefull 2. The actor is also on a special diet that will help him put on muscle weight.

Says a source, "Riteish's look is being kept under wraps for now as director Sajid Khan wants to surprise audiences."

As the sequel also stars John Abraham, RD has lots of competition -- at least in the beefcake department. Aai guh! That's what Riteish must be saying while sweating it out.