Sounds innocent, albeit non-conventional. Think about it this way - black leather is a conventional fantasy and I have even seen "leather families" on FetLife.

There is a cottage industry catering to the black leather fantasies. The whole bikers' world is adjacent to that, too.

Why not have a white underwear fantasy? There is no material difference.

I would recommend you open a FetLife account, write stories about your fantasies, and maybe fine like-minded people who would normalize your experiences for you.

By no means is this grounds for any guilty feeling, that is for sure.
And, I have no fetishes, so I am not writing this from the vantage point of a fellow fetishist, but from a completely "traditionalist" vantage point.