I think I'm going to move my roommate's things.
Why are you gonna move his stuff?
I'm tired of his bad behavior, he just has to move.
I get why you're mad, but you should really ask him first before you touch his belongings. He might be really mad if you're touching his stuff without permission.
He's not home, so he's not going to know anything about this.
Even if he's not home, he'll notice when he gets back and he'll be upset with you for moving his things around. If you want to move his things, have a talk with him and make sure he's OK with it first. How would you feel if your roommate started moving your things around without your permission?