had offered the sofa, an airbed, or another pull out but apparently again all of that is abusive. I have offered him even to use my car to go home say at 9-10 in the evening and come back in the morning but that’s “too much messing about”. The problem is any solution I’ve come up with I’m also told how wrong I am. Again keeping in mind I haven’t asked him to be here.
OP, I recognise this. Not you specifically, but abusive men like this. SIL had almost exactly the same issue. HIS view was that he should be with the DC at her house (in his case because he doesn't have a suitable place to have them) and he was outraged when she put boundaries in place around that. Eventually, she had to stop him coming at all - sad to say, as a result, they haven't seen him for nearly a year.
You need to nip this in the bud. Does he pay CMS or do his nights at yours count as him doing his share of overnights!?
I appreciate how hard this is if you've had years of this man's disordered thinking when it comes to you, exacerbated by an ill child. Here's what I would do:
Discuss with the carers. Tell them your concerns that when your ex is staying overnight, it does not particularly help you. Ask if they have any particular reasons to believe he should/should not stay overnight on occassion.
Then decide if you are wiling for him to stay - my instinct would be that he can stay a few nights, but not the number he currently does, but you might decide a flat no.
Then, feel very clear in your own head that in your home he sleeps on the sofa/blow out mattress etc.
Then, I would tell him this while the carers are there. Explain that you are comfortable that you don't need him this much and tell him what you think makes more sense. Also calmly tell him that you will be making up a bed on the sofa/mattress etc in future so if that impacts his decision on how many nights he spends at your home, you completely understand.
However, be prepared fo rhim to use this to punish you. He will accuse you of all kinds of things (like taking him away from his children, abusing him, manipulating him etc). He may well also threaten to punish you, most likely via the children - he won't visit, he won't pay (if he does at the moment - I'm guessing he doesn't) etc.
My best advice is to feel 100% confident that no rational person would think that what he is demanding of you is necessary or acceptable and remind yourself that he is not rational. He will be believable and you will feel bad because, and htis is crucial, he actualyl DOES believe th shit he's telling you. But that's the abusive behaviour as a result of his own disordered thinking.