I know my father considered it although it was BPD mother who made the most threats- empty ones. While I think my father had the sense to not discuss this with kids, because of the conflicts- at home where we saw them, and BPD mother's threats, I eventually asked him. As kids, at about 9-10 like yours, we really didn't know enough to ask.
From a parents' perspective, it must have felt shocking to have a teen daughter ask pointed questions, but BPD mother was bringing up their relationship issues. That was not appropriate but we heard it.
I know there was more to it but being confronted, he did say some. I had no idea at the time how unable to manage on her own she was. It was well hidden and Dad's support covered a lot of it up. He didn't reveal it either, he must have known.
Some of his responses were probably covers for the situation. He sometimes said it was too expensive but so was BPD mother and her uncontrolled spending. At one point he mentioned doing this and letting her find someone else. She was very attractive and now I see that would have been the only way she could have managed.
But he also did love her in a way- and when she could pull herself together, she was very charming. Sometimes he appeared smitten with her. The push pull I think also gave him some hope. It's also possible that there was less stress once we kids were grown and out of the house, and he didn't have the parenting duties in addition to her. By our teens, we were very self sufficient. However she remained a challenge.
I think he did feel trapped but I think a part of that was feeling responsible for her. The stress on him was apparent, even if he didn't talk about it. He was irritable at times and snapped at us. It was different when he was alone with us, he was more relaxed and engaged.
He did feel responsible for us kids and in her era, custody went to the mother. She would have pulled it together in court. Also in their era, many women didn't work outside the home. She had no work experience, and was unable to function in a job even if she did. I think he felt responsible for her.
Where things unravelled was when he got sick in his elder years and she didn't have as much of his supervision and emotional support. That is when I saw the full extent of it. Knowing he was very ill, I did bring up concerns about how she could manage on her own. I offered to help manage their finances as I knew she'd mismanage them. She refused. Eventually she did mismanage them. I had to have boundaries with her but stay in contact with her and was the next of kin contact in her elder years. Fortunately there was enough funds left to cover her care facility.
My own take on this is that what is best for your own mental health is the best for the kids. If staying together leaves you stressed and drained, then that affects the kids too. They are going to see their mother's behavior whether you stay or not. If you do stay for the long run, be prepared for all the stages of this. As difficult as divorce is, if it did come to that, there might be resources in place for your wife that she is on SSI which could make her eligible for Medicaid in her elder years if needed.
One thought is to seek out this kind of information- what is she eligible now and later, even if it doesn't come to that. I did seek this out for my BPD mother- what are the options for her care if there are any. While the elder years are a ways off for you two, having the information itself may help you with plans whatever direction you choose.


