Im just curious, what do you call each others parents?

If married, seeing someone, or what have you, what do you call the other's parents? By their first names, by their last? Do you call them mom and dad, or do you add on a mom "d" or whatever to represent debra, your mil (randomly chose the name lol).

I call mine by their first names. They havent actually expressed to me a desire for me to call them mom and dad, and I feel too awkward about it to do that. Barely want to call my own parents mom and dad! Ha! My husband calls my parents by their first names also. My mom signs cards, "love momma D" (short for deana).

So, how about you?