And who knows, maybe it's because they've asked him not to go. Bottom line is, we don't know what the situation there is, do we. It doesn't sound as if the kids have accepted their stepmother.
It's not always easy when parents are divorced, both my husband and i have divorced parents and step parents. His father, even though he wasn't always there once his parents were divorced, did pay for my husband's education and tried to help out my husband's sister.
I'm not going to rush to judgement since it seems to me we're not getting the full story.