This is my experience, with my mom and dad. My mom would get offput, saying the same thing— it’s probably different big/little things for you, but the idea’s the same…— my dad would always want to do big extravagent things, go to the movies or out to fancy dinners at the drop of a hat, do big things for birthdays, remodel the house; but he’d never clean up anything he got out (he wouldn’t put the milk back in the fridge and it’d go sour, things like that) he’d fling his socks at the dogs then leave them on the floor to pile up, he’d use his laptop then leave it in the middle of the couch, he’d sit and watch TV while everyone else was cooking/cleaning, etc. I could keep going…
I’m not saying that you do any of that!! In fact, I’m sure you don’t do those things. And I’m sure you do less ‘little things’ than my dad did. I’m just saying, those things he’d not do were, by themselves, fairly small and insignificant. But, with the livingroom full of dirty socks, empty snack containers, dirty dishes, computers and their various cords, it all built up and got kinda gross… then my mom (and me and my sis if we were around) would have to clean it all up to sit down.
Like @ItalianPrincess1217 said, next time you hear her hinting at something, anything, make a note of it. My mom’s pet peeve is cleanliness. Everyone has their own, that little, harmless things set off. The little things your fiance sees probably won’t easily and conveniently fill up a room of the house, and are things you probably think nothing of. But I bet you’ll be able to pick up on what bothers her.