My husband told me he likes feet and I'm trying to understand it

I hope it is alright for me to post here. I do not have this myself. My husband told me a few weeks ago, after eleven years together, that he has always been drawn to feet, and I have been trying to get my head round it ever since.

I am not upset and I have not made him feel bad about it, or I hope I have not. I just genuinely do not understand what it is. When I look at a foot I see a foot. He clearly experiences something completely different and I cannot picture what.

So my question is really for the people who have it. What is it like from the inside? Is it about how they look, or being close to them, or something else entirely? And is there anything you wish your partner had understood at the point you told them?