For the last time, I do not TAKE OFFENSE, I just think it is WEIRD.
I made a distinction on the previous page between guests that the person knows and guests that they don’t know. If you are in fact inviting a “friend of a friend” that you have never met or barely know, it’s perfectly reasonable to lock your bedroom door. But if you are inviting someone you know well, you should be able to trust them to stay out of your personal space and/or control your children.