Rather than making assumptions as to how his father views the treatment of Bob, Bob should talk to the man about what is grinding his gears. The father may be looking at the situation with an entirely different perspective than Bob does. From the outside looking in, and only what I know from these boards, Bob's a college graduate in his late 20's or early 30's who's living at home with his dad; I believe he's even said that this is his step-father, which can change the dynamic all that much more. I believe that the situation is Bob living there rent free, based upon things Bob has posted in other threads, and as such, his dad might be making assumptions as to certain tasks required of Bob. At the same time, his dad holds the ultimate trump card in any decision - it's his house and Bob's likely living there rent free, or at a reduced rate, and perhaps he's not contributing to the monthly gas, electric, cable/internet bills either, as is often the case for adult children living with their parents. Pushing the roommate idea without consulting his father could also cause his father to start demanding money for room and board or Bob needing to find another place to live.
I say all of that just to say this: Talk with the man, Bob. It might be difficult, but if this stuff is truly important to you you'll need to talk with him. It's a better solution than turning cold towards him without explanation.