If I was dating a guy and his ex wife called and said she needed him to watch the kids because she was sick and needed to see the doctor, he sure as heck better cancel OUR plans and do that. As long as she wasn't a woman who took advantage, I would have lose respect for a guy I was dating who wouldn't help out the mother of his kids by caring for his own kids because he had to GAL.
On the other hand, if she called all the time still expecting him to step into husbandly duties like fixing things around the house and he canceled our plans for THAT, well, I'd have to set up a boundary. But I fully expect any dad I ever date to be willing to take his kids for emergent matters.
