ExH and I have been separated a good few years now. We have 70/30 split technically, although our eldest spends most of his time here, and exH doesn't have them much in holidays. ExH is a high earner, but is is self-employed so what he declares as income is not what he actually pays himself as he puts a lot of expenses through his company (yes, I know this is illegal but not much i can do). He pays maintenance based on his declared income and on the number of nights he's meant to have the kids. I haven't asked for more as tbh he's a nightmare to deal with and we get buy. I have a good job and am sensible with money. When we were divorcing he stopped paying himself anything until I paid a solicitor to get involved.
Anyway he has started refusing to buy the kids anything except food when they are at his and has told them they need to get me to buy them stuff to keep there as he pays me a "bloody fortune" in CM payments. To add insult to injury he splashes money around himself like it's growing on trees but won't buy his kids deodorant or clothes ffs!
Any advice on how to manage this? Shall I just provide the kids with stuff to make sure they are provided for there or make a fuss and have himself potentially stop paying altogether? Kids are teens btw so not cheap!