I think that is very wrong: we all deserve privacy. Try talking to her in a neutral way: Mum, I feel really Gary who’s Gary weird science shirt when you come into my room without knocking ( or whatever it is she does). She might be more inclined to listen if she realizes you are upset. Good luck! They are joyous because they have a new supply that isn’t sucked dry, used up and thus boring yet. They are enthusiastic about this new supply, because the reality hasn’t set in yet and they think that this person is more perfect than the last one, and that the relationship is better than the last one because it was the old supply’s fault for some reason, any reason, that the relationship went sour.