When I was married I always called my mother in law by her first name. Now divorced- we still stay in touch... and referring to her as simply "Mary" doesn't seem enough.

I only call my actual parents by "Mom" and "Dad," and my stepmother is simply "Linda," although she means as much to me as if she were a Mother...

Excellent question, and clearly one that is debatable in different situations.

:-)

My icky ex-brother-in-law used to call my parents "Mom and Dad" which always drove me insane. John and I have only been married a little over a year. I think we are both trying for the 1st name thing but it is still a little awkward.

By awkward, do you mean it feels easier to go with Mr. and Mrs.?

I feel very comfortable calling my in-laws, Martha and Roger. I don't know if they'd prefer Mom and Dad, but I'd feel awkward with that. Growing up, my two best friends' moms both insisted I call them by their first name, so that's what has always worked for me when addressing friends' parents. Some parents prefer the more formal "Mr. and Mrs." out of respect, I guess. And I'm happy to comply if that makes them more comfortable.

I have no parent-in-laws, but I have to agree with Stef, the mom and dad thing w/our ex-in law always seemed like it was premature. I find most people can get away with saying nothing at all in most cases.

by awkward i mean i try to avoid referring to them at all. When forced, I use first names.

I'm shocked that nobody has answered "Mom and Dad." Has that gone out of style? Does everyone find it freaky? I thought it was much more popular and I was more an oddball using first names only.

my ex- fiance's mother used to always tell me to call her mom and always signed cards etc. as mom. i called her by her first name though. my mom & dad are the only ones i call that. growing up i always called people's parents by their first names because that's how my parents introduced themselves and how my good friends parents did too. i was corrected or scolded by a few friend's parents tho. then i just never called them by anything. my parents don't like to be called mr. & mrs., one friend in high school comprised on mr. & mrs. b. most friends at that time just seemed to love that they wanted to be called by their first names and most friends still seem to love addressing my dad by his name- buzz.

There's definitely something fun about saying, "Hi, Buzz." I never miss the opportunity to do so when he answers the phone.

my (real) mom used to call her mother-in-law "mom".

I think mom & dad is kind of weird, as they're not. And I think that Mr. & Mrs. is inappropriate since it is at least somewhat of an intimate relationship (I mean, you're having sex with their kid). I don't call anyone Mr. & Mrs, by the way, unless I absolutely have to--which I can't think of a reason right now. So, yeah, first names, although I usually avoid calling them anything by prefacing any of my sentences with, "hey" and looking in their direction.

I agree with Steve for the most part. However, I can understand if a person has a troubled relationship with their own parents, or if their own parents have passed away and/or if the relationship with the in-laws is very close and paternal in nature, why they might start call in their in-laws "mom and dad".
Normally I would say that using mom and dad is in general yuck. But in my Mom's case (also alexis' mom), her parents rejected her when she married my dad and her own Mom died very young. My Dad's mom always looked out for her and treated her like a daughter so it always seemed very natural that she would call her Mom. In fact, when my Grandmother was dying of cancer, it was my Mother who went and helped my Grandfather with her care and medical bills.
Actually, now that I think about it, her other daughter-in-law called her "mom" too. Maybe with some people it just works?

Hey, i really just meant that for me, using "mom" and "dad" are weird. I can see a ton of circumstances where it would make sense and feel right for people. Thanks for pointing that out, Stef.