Looking for some advice on what a reasonable solution is to this toxic problem.
My granny died about 15 years ago, and for much of the time since then my granddad has lived with a woman we'll call Vera. They got together a year or so after granny died and had, for many years, a very happy relationship.
Things have in the last couple of years turned terribly, terribly sour. Vera is a few years younger than my grandfather and helps him a bit as he's become increasingly frail. For this reason he feels dependent on her. But he is terrified of her and I don't know when things changed exactly. He is now convinced she is only with him to try and get her hands on money (he is wealthy), he believes she has stolen from him but there is no evidence of this, he has told us that she has said terrible things to him (about disinheriting my dad and his brother, about me and my siblings / cousins being a drain on him) but we haven't heard her say these things ourselves. He is frightened and miserable but he can't face doing anything about it.
He seems compis mentis - no other indications of dementia or mental frailty at all. His depression (intermittent throughout his life) has returned full force, but he doesn't ever seem confused or uncertain. But it's so hard to square this up with the Vera we know, who has always been a nice lady and who behaves as normal on the rare occasions that we now see her.
Vera has two very difficult adult sons - one is a gambling addict who has had much of his inheritance in advance and lost it. He spent several months living with granddad and Vera and granddad several times found him rifling through papers in his private study etc. The other abandoned his wife and Vera now supports her DIL and grandchildren financially as her son has little to do with them. I don't know if they have anything to do with the present situation but they could be putting pressure on Vera and causing her to behave differently? I don't know.
This is coming to a head because Vera lives with my granddad but owns her own home which she is now planning to sell to free up money. My granddad is concerned that this money will go to her gambling addict son and she will be left penniless and with no assets. He wants to draw up a cohabitation agreement to ensure Vera gets nothing if he dies, to protect my dad's and uncle's inheritance.
But I'm terrified that his concerns about Vera - who still seems to be behaving normally to us - are paranoia and he's going to end up trying to force an unfair agreement on her and leave her in a terrible position. I don't know why they don't just break up when there is clearly no love and trust - but I think he feels dependent on her. I fear he's using her, but I also fear he's seeing a side of her that is hidden from us and that we will fail to support him.
I don't know how to proceed from here. We keep having fraught and emotional conversations with him that go nowhere. He seems paralysed by anxiety, and I just feel helpless in the face of it.