My elderly mother who has dementia, thinks my father has recently run off with another woman. She forgets that he passed away 35 years ago. At the beginning when this came up I told her the truth and she said I was wrong. After that, if it came up I would say I didn't know where he was and would try to distract her. That did not work and seems to made things worse. Right now she doesn't trust me. She thinks I know where he is and secretly visit him. She keeps asking more and more detailed questions about why he left her, what he told me, where he lives, do my adult siblings live with him etc. She wouldn't believe me if I said he was on a trip since he never really travelled. Looking for ideas on what to say to reduce her distress, stop the questions, and somehow rebuild trust.