@mummy917
Thank you for starting a new thread. I think all of us want to keep supporting you on your journey even if it seems that our support isn't always what you want to hear (and I include myself in that).
This is just a point to ponder. You say you pick up the slack because if he doesn't step up as a father the children won't have 'what they need'. But ask yourself, what is the worst that will happen if you stop? Will they truly suffer from the lack of whatever it is or will it just be an inconvenience? Obviously, if he isn't feeding them or giving them needed medications, that's one thing. But, for example, a lack of potties doesn't make them 'suffer', it just delays potty training a few days. This makes things harder for you, but I think the twins aren't going to 'suffer' for it. Do you see what I'm getting at? He is never going to learn if you keep bailing him out. You've stood strong on many things with him. You can stand strong on this, too. And chances are if you refuse to 'bail him out', chances are his mum will. But that's fine, because her doing so doesn't affect you.