Exactly. I guess I can sympathize with parental anxiety, because there are many people who would agree to not leaving someone unsupervised with the kids and then it would happen anyway, in a "just for a minute" or "it was an emergency" sort of situation. But that's also just a risk with free familial childcare.

In a hypothetical non-bigoted version of this question that was simply about potential danger, the parent could try to explain their concerns in a way that doesn't sound unreasonable or personal, but I don't think they could expect accommodation necessarily. I definitely wouldn't expect them to get their way with an ultimatum.