Have NC as this may out me.
Been with OH 4/5 yrs we both have DC. None together. OH in forces when not away we have his DC every other weekend (unless his ex arranges other things to do with DC 
another thread).
He pays what I consider generous maintenance (more than my ex pays for my two) and drives over 1000 mile round trip every time we have his DC (he is based at opposite end of country to where his ex moved when she left him). Costing us prob £400 a month.
We also buy shoes, uniform, other things when we see they need them and he's paid for swimming lessons, school trips etc.
Ex will also get 1/2 his payout when he leaves forces (they were married 3 yrs he has been in 25).
She has asked for more maintenance (she gets £350 a month, works and receives housing benefit, tax credits). OH cannot afford to pay more as he contributes to our home here (where he brings his DC) pays for petrol, and for his room on base.
If she goes to the CSA he will prob have to pay more as petrol and other thinfs mentioned above are not taken into consideration.
I have said to him maybe offer £400 and appeal to the better side of her nature and explain about the petrol etc taking a softly softly approach. I am pretty sure she wants £500. I have said to contribute less here to afford it.
He says that won't work (they are both incredibly stubborn hence the divorce) she is to be fair quite materialistic and terrible with money (and the kids are always in falling apart clothes while she often wears labels - not that it is any of our business what she spends her money on) and has gone ballistic says he is going to dig his heels in and refuse to have the kids more than once a month and generally dick her around (trying to get through to him you will also be dicking your kids around :( ).
I am hoping it is his rage talking as I can only see the kids losing here (on what is atm a very stable happy arrangement for them). Please can someone suggest how I might support/advise him so we can compromise without him walking away from his DC or his DC being placed in the middle of a battle zone.
TIA.