> Also, an affair is only blackmail material in a society of prudes

No? All it requires is for Jensen to want to remain with his wife and for his wife to be willing to divorce him if she finds out he has an affair.

Or, even if we suppose he doesn’t care about his wife’s feelings at all, he might be very incentivised by losing half of his assets in a divorce. It’s worth many, many millions to him.

Very little involvement from society in that one.