and slightly churlish?.....
Ex pays the minimum maintenance possible. Often "forgets" and I have to to text him to ask for it. Refused to offer any money for DDs residential or equipment as "that's what maintenance is for". I asked for some help with uniforms and he said he can't do anything now, possibly end of Sept 
He has just returned from a two week holiday to Aruba and is taking DC away for 5 days next week.
He's just text to ask if I can pack kids summer clothes to take.
AIBU to tell him to bugger off and buy some himself? The kids won't suffer if I don't pack for them, he will buy them if he has to.