Not quite sure if fetish is the right word really.
My DP likes to wear certain underwear at night. He first told me years ago and then it didn't bother me too much. It wasn't much of a turn on but it was harmless.
Now he has more of this underwear than he does of his 'normal' ones. Everytime I do the washing it pisses me off. I have commented that I think it is a bit too much but he doesn't reply. If I say I know he has bought more, he says he hasn't even when I know the stuff I have washed is new.
If your DP really enjoys something that is harmless but you don't exactly find it attractive, do you just put up with it?