I think it's best to have a conversation about age-disparate relationships without using words like "gold-digger" and "predator," no matter how much we're "creeped" out by the age differences. Jumping to those assumptions really cuts off the conversation, because no one is ever going to defend a gold-digger or a predator.
The more bewildering concept is: What if they're not? What if they not toxic situations in which one party is "using" the other...or both parties are "using" each other?
What if they're healthy, positive, mutually supportive, loving relationships? What if those relationships are as healthy as our own--or more so?
That's the more challenging notion--challenging to each and every one of us whose initial reaction is "eew" or "ick."
In both of these situations, it is very possible that none of the players can be described as predators or gold-diggers. We haven't heard much about the Jamie Kuntz's 65-year-old "boyfriend," but Jamie doesn't really seem like he's gold-digging. And I can't really imagine Stephen Sondheim in the role of predator, and he's way too cynical to be taken advantage by a gold-digger. He'd see right through that and write a song about it.
At any rate, I wish them all well.