I'm a revert my sister and her boyfriend are non religious. He has serious mental illness specifically D.I.D (multiple personality disorder). He refers to his other personalities as alters and I've meet one, an 8 year old girl and there are several others. He has a genuine diagnosis for split personality disorder. My mother lets them sleep in the same bed in our home I feel like if i say anything it might get me put out. They've been together for years now with out him doing anything dangerous but he is just to damaged and ill for me to approve. I'm afraid he might wig out and hurt someone. what do I do if anything?