In his situation he can?t really win. If he pays her less he will be the ?bad guy? with her, her family, his child (if she is the type to talk to child about it), probably MN if she posted on here (which she might). If he keeps paying then he is bad guy with you as you are struggling and it doesn?t seem fair.
But its not fair, its messy and tricky when you split up and lose primary care of kids ? your worth to your ?old world? become measured almost solely on the value of your financial contribution. And yes you now have 2 households to support. But nobody cares except those in your ?new world?.
Until the divorce and contact is sorted out he is choosing not to be the bad guy with her and kids (and maybe courts) he probably feels its safest option. He probably thinks you are committed to him regardless of £££ and are taking a long term view on this.
If you leave him he will be worse off as will have to pay all that and then all household bills himself. You will be better off £££ but worse off emotionally. His child, who knows probably a mixture of the two.
I think you need to accept it, support him as needed and DETACH from the divorce and the ex wife anst. This is all par for the course with many people. It will settle down and, provided you have detached, it will settle down sooner rather than later. As for the negative comments about you just be cool, try to ignore, be nice and accepting and kind to his child at all times, they will come around eventually.
Dont ever expect his exwife to see your point of view, why would she see your point of view? She sees only hers, you see yours, your husband sees his. That?s the way people are.
Deep breath, stay calm, be nice in your thoughts about her, try to calm him down when he talks about her, make him see her point of view not because you want him to pay her more (of course not) but because it takes at least 2 people to have a fight, the calmer and more reasonable he is, the more likely she is to calm down and less likely she is to try to hurt him through this process.
Encourage your DP to ask her to seek mediation on the financials. Court is adversarial. Dont suggest CSA unless you want to throw petrol on the situation, they are a bunch of f**kers and anyone who invites them into their lives through choice needs their heads checked.
Forget the whole work/SAHM thing ? you are a single parent, why would you consider not working? You know how life can change in a heartbeat. She is not the reason you are working, you are working to create opportunities for your family long term. She may well reach the same conclusions as you in future and so the same.