Do I tell the ex's wife what he's really like?

How old are the DD's? I'd be tempted to not reply and ask them to phone Dad as he wants you to change plans with them,

Age appropriate truth is what they need.

I’ve only read the OP’s posts but there was a thread here recently where a woman was dealing with this rubbish by every time her exDH threatened something or said something ridiculous her response was ‘Thanks. Let me know how that goes’ and NOTHING else. I thought that was brilliant. What he did to your DD about the birthday was really mean to both you and her but a response of ‘no worries’ or something similar would take the wind out from under him. And then don’t tell the kids - if he shows up they’re none the wiser, and if he doesn’t, then they’ve the same level of disappointment as they would if you’re feeding into his BS. Either way, he’s not winning.

You don't need to do anything, eventually he'll do something shitty to her as well.It might not be stealing money or cheating, but something shitty because that's what he does.
You should stop thinking about though put the energy into good things for you.

You need to move on, it’s as simple as that. Don’t let him see you eaten up with bitterness, being too focussed on what he is doing, judging his behaviour, his decisions, etc….. The best way of putting two fingers up to a failed relationship is to get on and enjoy every aspect of your new life, with your new partner. Maintain a cool, arms length, selective communication mode with your ex for your children’s sake, but try not to weaponise decisions taken about them.

Its not hard to do this if you really want to and focus away from him, don’t rake up the past, it’s gone. Become a new person, a new woman, embrace your new life, shed the baggage in all but access for your children. You don’t need therapy or counselling if you are strong enough to set and keep goals, but it’s back up if you can’t let go.

The best way to deal with his continued abuse is to not let him do it anymore. Definitely refuse to speak to him via phone - you don't need his voice in your head. All communication can be done via text, emails etc. That gives you time to compose a minimal, non-emotional response. He wants to wind you up so stop letting him do that! You're playing into his hands and he's laughing at how easy it is for him to upset you and paint you as the crazy ex-wife.

Don’t do this. Somehow, you’ll be made out as the ‘crazy one’ who probably just wants him back. She’ll find out eventually.

Grey rock. Stop talking to him on the phone. Just email or text only. Whatever nonsense he comes up with just reply with "grand". And ignore ignore. She won't believe you, and at the moment you're playing right into his hands anyway.

This is all you have to do. If he cancels, you just say "cool, let the girls know". If he doesn't and they are sitting there waiting, you tell them you don't know whats happening and to call him.

Stop covering up for him.

Great advice. Just say OK then bye must go now and hang up.

I bet she knows anyway. A genuine prick can't hide it for years. Enjoy your new life. Don't feed his fire.

I agree. I don’t think it’s just the dad being difficult here, I think the mum is addicted to the drama. Move on OP.

Don't answer calls and texts. Use a parenting app to communicate.

The new wife won't believe you, she'll believe him. However he'll show his true colours to her eventually, if he hasn't shown glimpses already.

Honestly- men like him don't change. She will find out sooner or later when he does the same to her

Not voting because he's an arse and of course you want to protect your kids. But you have got to get smarter than this, because you and your girls are the losers and always will be if you don't. You are only protecting their hurt feelings in the moment. But you are allowing him to undermine your relationship with the girls by covering for him. And you aren't allowing yourself to heal.
I'll repeat the advice, do NOT answer the phone to him. Text or email only, then you have evidence, but more importantly, you can take time out before responding. So all your responses can be calm and reasonable. You know, if all he's doing is having a go, you don't need to respond. You can just say "Noted".

I do feel for you because the guy is clearly a crazymaker and a wrong 'un - to hide money from his daughters, ugh...

But in a few years, your girls will start to see through him. And when he's calling you crazy to them - because he will, if he isn't already - they will come to you, and you can say 'Yeah, I phoned his wife up and told her a few home truths!' or you can say 'Yeah, but I rose above it and did the next right thing.'

I do advise you to see a therapist if you can - they can help you work through these feelings and stay calm in the face of his needling. 🤗

Also you worry a lot about how you look to your daughters. If you stick to written communications that is shut down. If he has written that he won’t do something, you pass on the info and if he changes his mind you can just say ‘oh, not what he told me’ and shrug. It clearly has nothing to do with you that he’s an unreliable parent.

NEVER talk to him. It's completely unnecessary.
Everything in writing via message or email.
This way, he cannot deny what he's said.

This is what my friend does with her ex. She simply never speaks to him except during pick up/drop off while the DCs are present.

You really haven't moved on.

Can you access counselling for yourself?

He sounds bloody unhinged! And no you weren’t cruel to tell your daughter Dad doesn’t want the germs to spread.
It’s hard because of course you don’t want to upset your children - especially when it’s not down to your doing. But I guarantee they see him for who he is. Stay strong OP, keep your head held high, ignore his rants - if he wants an audience then he has his current wife for that. Reduce contact to written only. You owe him nothing except communication about your children, and that’s factual communications such as arrangements, not ranting and moaning because he’s an arse.
It’s hard being the bigger person but your kids will thank you for it - as will your inner peace

I’ve pressed the YANBU because I think your feelings are completely understandable and of course you want to rebalance things, especially in the eyes of your mutual daughters. You’ve done the right thing by coming in here, getting it off your chest, and letting MN help you gain some perspective.
If you really are the better person you’ll know nothing great will be achieved by stirring up shit and playing tit for tat (he’ll win that game however it plays out)
Best thing you can do is enjoy your life and relax in the knowledge he’s irritated not be able to wind you up.

You said he puts you on speaker phone in front of her and shows her your messages. So my advice is to try to be calm and reasonable in your communication with him, that way he can’t show that you’re crazy because you won’t be being crazy.

Depends how you said it.
'Dad thinks it's best if you stay home this weekend so you don't pass your illness onto your siblings' - fine
'Dad doesn't want his new family to get ill so he doesn't want you' - cruel.

If the kids have phones then why do you need to get involved in arrangements like this or in splitting money for the jacket - can you not just say, Maisie dad left me a message about your visit this weekend, can you call him and sort out arrangements?

You probably should do. Cruel to be kind. If you want them to be able to spot a potentially horrible boyfriend before getting into a relationship with them, it could be useful to recognise that their dad is not the best man in the world.

She doesn’t care.
Their relationship is none of your business.
Telling her with evidence will not improve the relationship.
There are apps for separated parents to communicate through if he’s being unpleasant.
This wouldn’t be the flex you think it is.

I have moved on. I dnt even give him a seconds thought until he contacts me for the girls and just his way of talking and deflecting really triggers something deep in me and the anger comes to the surface.

You haven't fully moved on because he can still trigger you so much. You haven't fully moved more control in this situation by choosing how to react to him. If it is too difficult for you to control your reaction some therapy can help.

Where is your new husband in all this? You haven't mentioned him.
Sometimes it works for new dh and exdh to be the ones who communicate re kids logistics. This way you don't have to deal with ex's bullshit and he may treat a man differently. Depends on the personalities involved but I've seen friends who have adopted this approach effectively.