My dad always called his ILs Mr. / Mrs. Lastname. Funny, stilted and formal in retrospect, although my parents were married in 1960, so that's perhaps a sign of that time.

On the other hand, I call my ILs by their first names or, increasingly by their cutesy grandparent names.

Resisted calling them mom and dad because I have my own parents, thank you very much.

I think it really depends on the relationship. I am very close to my inlaws and think nothing of calling them Mom & Dad. I call them by their names at times as well though.

I avoid calling them anything at all. I was a teenager when I met them and they were Mr. and Mrs. So and so. It feels weird to call the, by their first names, even though I am an adult now, and Mr. And Mrs. So and so is obviously too formal.

I call them lots of things, mom and dad are not on that list.

I either call them by name or call they nonna and pop because my kids call them that.

I have family members that call their ILs mom and dad, i don't think it is weird I just did not feel comfortable doing it.

I call them Ma and Pop, because I call my parents Mom and Dad.

My in-laws are very old fashioned and I think they would like me to call them mom and dad, but I don't. It just feels weird to me. At first I avoided calling them anything ha, but I now call them by their first names.

No way.

Absolutely not!

No. I think this was much more common among older generations.

Haha! Hell no!

I refer to them as first names and it drives them nuts...

no, never

No, by first names.

No. That's seems strange to me, too. DW calls my parents by their first names, and I call her parents by their first names.

I always thought this was weird, but all of DHs in laws call his parents mom and dad. (He is one of five). I am not rude about it and do it occasionally out of respect, but I call them by name. Just curious if others do this.