To think he’s not doing anything wrong by stopping maintenance?

Unreasonable? I don't think so. SHE is on maternity leave, having a child with another partner, yet JACK kept on paying maintenance? Which means he's effectively paying for her new child? That's absolutely MENTAL!

You've also stated that Jack will still pay for what looks like EVERYTHING for the children:

'Jack has it made clear that he will not be requesting any maintenance from her and that he will carry on paying for everything as before (clothes, uniform, trips, hobbies, sports etc) and has offered to have their children more, do pick ups / drop off on her days, cover all sickness absences as he won’t have a work schedule but all hell has broken loose'

Yet that's still not good enough for this Anne person? Someone needs to take this woman aside and have a few well-chosen words with her. In effect, she actually owes money since Jack has been the RP but still paying HER for the extra night.

I actually think Jack is a bit of a saint putting up with his ex and her demands. She's with another partner, having children with him but HE is basically funding their lifestyle? Not on your life!

I think a key point here is that she asked him to have the DCs 4 days a week - unlike too many fathers who try to wangle this so they can avoid paying, then palm off the kids for their mum or whoever to look after

Add on the fact he's already been paying far more than he was obliged to, that the mum's made a free choice to take on the financial responsibility of more DCs and that the end of the payments had been fully flagged up, and yes - she's being completely unreasonable

It is in that his ex is using the maintenance to fund their lifestyle, rather than pay for the children!

How is her life not going great?

• She has a job to return to after mat leave
• Exdh who has always paid more than he was required to
• Exdh who has willingly stepped up to facilitate her prioritising her new kids
• new dp to share the load both financially and running the home (if he isn't pulling his weight she has made her fertility decisions knowing that given this is her 2nd with dp)

Any problems she thinks she has are entirely of her own making

How to tell everyone you didn't read the OP properly just found an (unfounded) excuse to be bitter about 2nd wives 😂

Her brother is absolutely not unreasonable, she has reduced her time with the DC and made him the RP why on earth would he fund her 2nd family whilst doing the majority of parenting? She's lucky he isn't requesting CM.
She made her bed....

Just be careful about he word ‘agreed’…my ex sent me a legal letter saying ‘we’d agreed’….what he meant was ‘he told me’…economic abuse in marriage doesn’t stop after divorce. Not saying this is what’s happening, but you’re probably too close to the issue to be objective.

To be fair, we all have a moral obligation to ensure that our children are provided for 7 days a week. That's a non-negotiable part of being a parent. Jack had the children 4 nights, buys uniforms, hobbies, trips etc. He is meeting his obligations.

After parents split, each will make their own choices and their standard of living may not align anymore. This seems to have been the case with Jack and Anne. The children now have 2 homes with different income levels, that isn't in any way damaging to the children unless one household is in poverty.

If we look at it from the other side, imagine an exH insisting that mum live in a house in a 'better' area, 'better' car etc in order that their lifestyles match for the children. People have different priorities, which may have contributed to the split in the first place. Or an exH insisting that mum doesn't take the children on fancy holidays because he can't.

They are 2 separate families now with children that overlap, they make choices independently.

In black and white according to child maintenance rules:

-Jack is the resident parent, he is entitled to receive child maintenance.

-Anne is not, she is expected to pay child maintenance.

-Anne’s amount to pay would be calculated according to the nights they spend with Jack (4 nights = 11.43% of her salary after taxes but this may be less or more depending on how they split school holidays)

-Anne is entitled to a small discount on the amount she has to pay as she has other children living with her full time (whether they are hers or not).

Jack was generous paying over what he was required to pay, Jack is still generous not expecting her to pay him child maintenance.

The tricky point is, did Jack cash in those investments BEFORE the residence order was changed recently in his favour? If so, Jack may be owing Anne £1,000s as the income from those investments will be considered as part of the CM calculation. If not, though for Anne but she gets nothing.

She is using the money to pay for her lifestyle.

That isn'f remotely the same. 🤣

Sadly though @Coco1379 you aren't "telling it like it is" - you are "telling it like you think it is" but have things wrong.

Best if you go back and read the OP's posts before you make any further mistakes

Yeah? I couldn’t be bothered to work out all the silly acronyms. None of her business then, is it really?

Maintenance payments for children in 50/50 custody situations are not mandatory and one should not arrange one's finances on what is a time limited payment, if the custody is not 50/50. I speak from experience here.

So OPs brother should also be paying to raise his sisters children?

She's his sister not a girlfriend or a wnd wife

Second wife syndrome. I’d make sure he’s generous to her in your own interests, not impossible that could be you in a few years.

He made her aware in advance that the child maintenance he was paying would stop at the end of her maternity leave. The children ‘will suffer’ because she doesn’t want to work to provide for them. Instead, she has two more children whilst under the delusion that her ex, the actual resident parent, was responsible for providing for her.

He is supporting his children, that’s all he needs to do. He isn’t responsible for propping up her household.

Doesn’t matter, it’s still between Jack and his wife. Telling it like it is: if there’s an agreement and it’s not being honoured it is the DC who will suffer. That has nothing to do with my marital status. I told my son the same when he said he was going to renege on the agreement he had with his ex-wife. I didn’t particularly like her, but she didn’t deserve to be treated like that.

Shes his sister not his girlfriend You obvs didnt read it properly in your eagerness as a co founder of the first wives club

I’m fairly certain the OP isn’t dating her own brother.

No one has bailed, it was agreed the maintenance to the NRP would stop when maternity leave ended and that the NRP wouldn’t be paying maintenance despite them having an obligation to do so. The NRP and her new partner could pay the mortgage by working.

I think Jack is her brother, not boyfriend

In short, Anne is a greedy cow. Your brother shouldn't have continued paying her CM when he started having kids more.
Is he sure both kids are really his?

You are definitely being extremely unreasonable. Picture this: you have an agreement with your ex either by court order or by consent. You arrange your mortgage, and budget on the basis of that agreed sum coming in. Then suddlenly ex decides to bale out of the agreement and leaves you high and dry. Then you have to suddenly have to find the shortfall to pay your mortgage. Where? How?
An agreement is an agreement and ought to be honoured. BTW this is between Jack and his ex wife. You are a girlfriend and naturally don’t like his ex wife (it’s a story as old as the hills). How would you feel if you were treated that way?

If the children are still financially dependent and her circumstances haven’t changed then it seems he’s punishing her but harming the kids.

If it’s voluntary and custody equal, that’s typically a high earning individual. CMS governs parents with income less than £156k pa. There is an expectation parents earning more than that will contribute, even in 50:50 agreements if there is a big disparity of earnings between the parents, this is so the child can have a similar lifestyle at both home.

If custody is 50/50 no-one pays maintenance. The ex DP is not expected to fund the household of their former spouse and their new DP, only to maintain their DCs. Whoever Anne is she is pushing it. She is not entitled to have her household maintained by her ex-DH. His contribution is now rather more than half of the care of their mutual DCs.