I think, akshat should have ask his parents before giving their bedroom to AD. He not only give their bedroom to live, also, he made many changes in their bedroom without permit. He should have know his mom better that she doesn't like anyone to touch her stuff without her permit.
I don't think so, in a really life anyone changes anything in parents bedroom for friends. A few days will be ok; however, long terms no way. I wouldn't do that at all.