This thread throws up a whole load of ethical issues and it is going to depend where you sit on all of that.
Legally he isn’t doing anything wrong. Morally a whole other thing.
But there are lots of questions, should his new partner not be allowed children in case this reduces his maintainence? Should she have endured only one egg was fertilised?
CMS calculates that maintanence is reduced when the NRP has more children, that makes sense, their obligations have changed. The income NRP had was previous allocated for himself and only his 2 children. That responsibility has now doubled. I am sure they didn’t plan twins but it has happened. As other people have said childcare would likely be at least £300-£400 a week for fill time for twins, so unless he earns a lot most if not all of his wages would cover this. so no one would be any better off in the long run, well technically he would still have to pay some
Maintanence so likely his current household may not be able to function/afford to live.
I imagine they have weighed up what they can/can’t afford and this has been the way it works. It’s not ideal, in an ideal world he would contribute. But maybe he can contribute with more time with the DC and then in things he can afford if he can buy things for them when they need it; but potentially not contribute weekly financially.
If his earnings are 0 he legally can’t be made to pay anything.
Both households have 1 income. This would be no different if RP decided to have another child and then her costs would have to split between that child and the others; maternity leave factored in etc, would they be penalised for not contributing what they previously used to and be expected to find the extra, take less maternity leave etc to do so? Probably not.
It’s just the way life works, people’s circumstances change, and this can happen overnight in some cases. Ideally all parent should contribute equally 50/50 in both money and time IMO but it rarely if ever works like that, because everyone is balancing things. It’s no different to being in a relationship, I imagine his new partner has taken a hit too, they have gone from having 2 incomes and 25% of 2 kids costs to cover (when they visit) to 1 income and 2 full time kids costs to cover.
If we are always expecting NRP to maintain the exact amount of maintanence, never to have more children unless they are earning an extra appropriate amount to fund that. It’s not realistic: both parents and entitled to move on and have further children if they wish to; and whether NRP or RP does this the current children will be impacted by sharing further with others, in some cases this impact will be bigger than other cases, it wholly depends.
It’s difficult yes, but legally not doing anything wrong and I do think some people have unrealistic expectations around NRP and how they should live their life when they no longer live with DC and these expectations don’t often join up with the expectations of the RP.