I have name-changed for this, don't want to be recognised. Long story short (trying to stick to the relevant stuff):
DP and I live together, and I don't think his ex is fully over their separation (I was not involved).
As DP has told me, part of the reason they split was due to a mental health condition that she refused to have treated, and which manifested itself in breakdowns and rage, and the family having to tiptoe around her moods and needs.
I'm understanding and sympathetic towards mental illness, however, I think that she uses these 'breakdowns' to control DP.
I loathe claims that people suffering from mental issues are putting it on - but these breakdowns only occur when DP does something she doesn't like. For example, she was compos mentis and together when they had a severe trauma in the family, but will have a breakdown when DP wants to take the DC to a place she doesn't approve of (i.e. a theme park). Breakdowns involve screaming, shouting, saying she doesn't want to live, can't cope, hates the DC - she will then lock herself in her study for a couple of days, so DP has to drop everything take over sole care of their very traumatised DC (not a problem) but also her. FYI she has PC but he sees them regularly - this extra care is outside of the arrangement and she doesn't have breakdowns when they are in his 'planned care', only when they are in her care.
This has been fine - I have held my tongue as it's not my business. I have no doubt that there is something wrong with her, but she uses it as leverage to the point where she has said to DP that if he saw me less, she would attempt to get counselling. DP told her that this was not a deal he would be involved with.
Anyway. Not really my business. When DP and I moved in together, she had a complete meltdown. After demanding that he not move in with me, she has now locked herself in her study and will not communicate apart from screaming. She doesn't care for their DC and is refusing all forms of treatment. As a result, DP has had to basically move back IN, and hasn't spent a night at our new place in two weeks. I think she is abusing her children to get DP back in the family home, which horrifies me. Also, selfishly, I miss DP.
As long as she continues to say she can't go on, DP will always go running because of guilt, and I am starting to suspect she will never stop this. DP's parents have advised me that she has always been like this, and had previously isolated DP from his friends and family with her behavior. They also mentioned that DP had left her in the past, but had gone back because the threatened suicide and couldn't care for the DC - this is the first time he's stuck to his guns.
I understand DP's predicament, I want to support him the best way I can but feel out of my depth. Just - what do I do?