Help! What is fair in this situation?

[DonkeyFacedCunt]

Can you wise vipers please help me work it what is fair in this situation. No doubt xh will have his own ideas, but I want to work out what I think is fair to start off with.

We have the same financial agreement as part of our divorce that the CMS recommend: 20% of his pay for two children. The difference we have written in is that this continues for them until after university.
As you may know, the 20% is not equally split. It’s 15% for one child and 5% for the second.
When first dc went to uni he agreed to carry on paying (as written into divorce agreement) but wanted to give the 5% directly to dc at uni. I agreed that this was fair and this is what has happened. She stays with me in all uni holidays and I pay all food and housing bills while she is home (she pays for herself at uni with help from my dad, the CM money, and working in the holidays). She is very fortunate to have found a job that she can work in the holidays as much as she likes. She works pretty much all day, every day and therefore doesn’t have to work in the tern time.

So far, so good, but younger dc is off to uni in September.
On the one hand, it obviously isn’t fair to older dc if younger one gets 15% of the CM. Older dc has one more year of uni left, so potentially for that year they can split it 10% each. What about the following two years? In theory xh would have stopped paying for first dc, as she will have finished uni, but still be paying for second at 15%. Assuming he doesn’t contest this. Is it fair for second dc to get all the 15%? I could suggest that she gets the 5 or 10% and I get the remaining as will still be finding her in her in holidays etc but I expect he would say no to this. He could continue to give first dc a bit of the money even though she would be working but I am not sure that’s fair either as second dc won’t get this.
To add to the mix, second dc is going to find it harder to get a term time or holidays job at all as she is ND. Even if she does manage get one she certainly won’t have the earning power of first dc, through no fault of her own.

what do I suggest as a fair agreement to xh?

Thank you for reading. I hope it makes sense and please let me know if you have any ideas!

That is a tricky one! I think ultimately you will need to speak to your XH about it.

assuming a 3 year course could you do something like this
Child 1: 5 + 5 + 15
Child 2: 5 + 15 + 15

Child 1 gets much more for their last year. Child 2 more for years 2 & 3. Clearly child 2 ends up better in this situation.

To even it out your dad stops supporting Child 2 in years 2 & 3 (depending on amounts not sure how much this helps).

Alternative is you could ask XH if he would give child 2 - 5% each year and with the difference an isa set up with a lump sum to them both when they need it (house deposit / weddings etc).

Appreciate annoying with nothing towards your costs for holidays but don’t think there’s a way round that other than charging rent which seems harsh (if new).

No, I have fully accepted that I won’t get help for them even though I will still have a lot of costs. I may ask for dc2 to contribute towards her own food in the holidays if she does have 15%.

I am sure xh would be delighted not to pay for dc2 in year 2 and 3 but I think the only one that benefits is him!

I think it would be fairest to split it in some way, as per your suggestions. Thank you.
think I’ll need to sit down and have a conversation with xh about it. Which is very annoying indeed. 🤪