My housemate wants to trade rooms, but there's no way I'm going to.
Why not? Do you have a problem with trading rooms?
I manage my room the way I want.
That's fine. It is understandable that you want to have privacy.
Fuck you. It's not about privacy. It's that I want to keep doing my room my way.
You don't have to be rude about it. It's okay to want your space to stay your space. You should express that in a polite way though, to me and to your roommate.