My wife is not into any kind of sex let alone the fetish scene.
My wife lets me wear my diapers and will put me in them and change me (well, she'll do wet ones--I've never asked her to do it when they're loaded and don't think she'd want to go THAT far, but otherwise she doesn't care if I do it and keep my distance).
But she absolutely does not understand the fetish thing. She understands that I love the way my diapers feel against me when they're warm, wet and loaded. She understands that I'm aroused by how they smell. And she understands the excitement I get from wearing them out in public, risking being seen, and being humiliated over it.
But she doesn't understand how just seeing them / touching them / being near them is exciting to me, how I get excited just taking everything (diapers, plastic pants, sissy clothes, etc) out and being surrounded by them--or how I "love" them. It's weird, but when I put them on and start to use them, it's almost like they "come alive" for me and become the object of my desires. (One day maybe I will expound upon that in another post).
To her, it's only possible to love another person--not an "inanimate object". Which is fine. I think that mostly men have fetishes--I've read of men having fetishes for diapers, panties, women's clothes, women's shoes--all sorts of things. I don't recall ever hearing of any women with similar desires (other than that scene in the movie "Porky's" where the girl gets horny when she goes into the boys' locker room).