Basically, xp contributes nothing financially towards our 3 dc and hasn't done since we split 4yrs ago. He doesn't work, because he doesn't want to. He claims JSA and has a private pension.
I am certain he is not as poor as he claims.
I get £5 a week from his JSA, between the three children.
If ever I ask for money for things for the dc, like trips etc, he says he can't afford it.
Anyway. I ashed him last week if he could take the 2 youngest dc to Asda tonight to get them halloween costumes. I said i'd give them £10 each. He agrees, and then yesterday says he can't take them because he needs to go and see a mate 
. I made it plain that I wasn't happy and he said tough, he'd take them on Wednesday night (costumes are for disco on Thurs).
So, 6pm tonight, he turns up and says that he txt me last night saying that actually he could take them tonight (he didn't), and starts ranting and raviing because a) they are not ready, and b) i haven't got any cash on me.
So, eventually he says he will take them anyway. So presumably he has cash on him for the costumes, but the question is, do I give him the money back ? Or consider that it is a contribution that is well overdue ??
The good person in me says, that I said originally that I was paying for them so I should. But the other part of me thinks £20 is a miniscule amount compared to all of the stuff I pay out for the dc.
WWYD ???