YTA for even making that snarky comment to your kids. If you got that impression from that conversation you should’ve not said anything at all to them. You ask their mother if there is financial issues. Teenagers like receiving money. You are making your own assumptions. For all you know they might just want the money to use as they please. They didn’t even voice to you that there are concerns. That snarky comment is very telling that the kids have to sit thru snide comments and questioning about their mother. Be careful of that because it might come back and bite you in the ass later on. Resentment will grow and it will be directed at you.