Five characters are, from one point of view, all about the same age.
Meanwhile, from another point of view, one woman is young enough to have been the other's daughter; that other is young enough to have been the younger man's daughter; and the younger man's -- well, not young enough to be the son of the other men. But one is at least ten years older and one about five.
This means that the father of the man in the middle is -- well, pretty old. He didn't get any magic mucking about with his age, and he's old enough to be a great-great-grandfather.
Hmm -- he does, at least, become a great-grandfather in the course of the tale.
It's interesting to reflect on how the other generations fit -- I already knew there would be one fairly elderly father (hmm, he's going to become a great-grand father, too, but at least at an age where that is reasonable.)