Back in the day, dads would often develop and enlarge family photos right at home, say in the bathroom, to the great delight of the rest of the family.
Surely more than one of them back then also thought about capturing their partner in some naughty way too, "since nobody else would see it anyway" :o)
I'd be quite curious how well they managed to talk their partners into such daring shots back then, given that erotica didn't pop up on every corner quite like it does today, and the peak of any sexy imagery in public was probably an ad for ladies' stockings.
But since men back then were at least as good at sweet-talking as we are today, I have no doubt that plenty of interesting visual material was created.
Some of it may have already been found by their descendants, but much of it is surely still waiting somewhere in an attic behind a beam to be rediscovered...