I've decided that in English, every way to address your inlaws is weird until you settle on something specifically with them. "Mom" and "Dad" or "John" and "Jane", both will be weird until you've used them for a while.

And if they don't like what you picked, you'll know pretty quick.

Mumble years ago I started using "Mom" and "Dad" as soon as we got married; my wife did the same with my folks — and my folks did the same with my grandparents.

It’s somehow both too familiar and overly deferential. Vis-a-vis my wife’s parents, I’m not a child, but an adult, though of less seniority.