I've told him before that if I accept money directly from him child support might close my case.
Hmm, would that really happen? If you think so, please confirm with the CS agency exactly what factors are involved that might even remotely disadvantage you. You of course don't want any pending actions halted just from a clueless mistake on your part.
Wouldn't the above explanation to the ex, if it was worded that way to him, make him want to try really hard to throw money your way outside the framework of CS? Remember, they love delays so he might think this could derail the train for a while. Instead, go ahead and hit him in his wallet, "If you give/gift me or our child any money, it won't reduce your CS obligations by even a penny."
That said, it is a time of year when even disordered people, some of them anyway, can do something nice, even despite an overall pattern otherwise. I can imagine that if I were messed up I'd try to avoid facing huge debts and prefer to send a token gift. Without knowing your agency's money handling rules, I can't say how you should view it either way.
