I just have to say, I really like my future in-laws.
They are so flexible and easy-going.
A few days ago I had an impromptu dinner with them when they were in town, and I was able to bring something up that I'd been battling with. FI's gram lives where I work, so I have had a business relationship with FI's parents for longer than we've been dating. I've called his parents by their first names for a while now, but it's starting to feel awkward to do so when we're in more personal settings. I want to be able to address them by a "nickname" of some sort. So at dinner the other night, I explained where I was coming from, and asked if they had a preference on what they wanted me to call them. And they said I can call them whatever I like, anytime!
So I think I'm going to start calling them mom and dad, even before the wedding, since that's what naturally wants to come out anyways.