My mom had a spoiled kitty who used to do this. He would choose other places and things too, like her coat or something, but he did the bed a few times. We never found a way around it. He only done it when left completely alone in the house for more than a few hours.. he didnt approve. This kitty my brother had found along with another in Germany and he raised them (they were a week old) so he was very people attatched. Felix went outside one day and never came home, but some have swore they spotted him at another house. We think he moved. (we had a cat growing up that done this, but the sweet old couple took good care of him and we left him with them)

Maybe you can keep him out of the room? Im not sure how to fix it...