My mum has just been round to visit. Apparently my dad is regularly accusing her of having numerous affairs throughout their marriage of nearly 50+ years. She hasn't and finds his accusations very upsetting particularly as there is obviously no way of proving that she hasn't had an affair. She has found it all so distressing that she said she had worked out how she was going to kill herself. He had a troubled childhood: his mother was not married to his father and he went back and forwards between his mother and his grandmother until he was a teenager - his mum did continue (apparently) to have numerous affairs throughout his childhood. They are both in their late 70s and I am at a loss how to support my mum other than to say she is always welcome here - the suicidal thoughts also really worry me. I did wonder though whether this could be an early sign of dementia - I haven't noticed anything else but obviously I'm not living with him.