To set a bit of background - my ex has our child every other weekend and half of the holidays. We have a formal court order in place and CMS to work out maintenance payments. This has worked well for a number of years as we have nothing to argue about and I'm reluctant to change this.
He has recently asked that when the yearly maintenance review happens by CMS we switch to an agreed amount between us. I asked if this was because he had a good year last year and it was due to go up. He said that he had an ok year but received bonus payments and commission too which may make his payment for our child higher. He said the reason he wants to agree a different (I assume lower) figure was "cost of living and paying off debts from a holiday he took his partner and our child on".
I don't want to agree a different sum as the cost of living is effecting everyone not just him and don't think him having an expensive holiday should make a difference to the maintenance payment he is due to pay but also don't want to argue or fight with him.