Not all guys have a “fancy” of feet I have to say. Guys who like feet are said to have a feet fetish. Unless they are all from the Victorian era where showing the ankles are probably considered provocative. Anyway, getting turned on by feet is actually pretty common, our brain is wired to get attracted to them, just like how men are attracted by breasts and butts. Although, unlike the latter two, where you can probably categorise preference by sizes, feet fetish are more varied, being more anatomical rather than visual. It’s not really hard to imagine how it isn’t so special, something like picturing how a girl taking off her pair of stockings can be sensual.
The variety of list includes, but not limited to, pantyhose, barefoot, footwear, boots, the toes and rubbing or stepping on things. It’s not that weird like you think it in the way that some people prefer lingerie over another, just apply this to a dressed-up feet. Some like the pronounced feminine odour of it, other like the touch of the feet on their body. You know how some old men in their 50’s would wear tight stockings or pantyhose under their pants and claim that they “like how it feels on their skin” when confronted? That is also another example.
So why do guys like feet? Arguably, the view of feet as a sexual object seems to be innate in human. Men prefer women with smaller feet as shown by foot fetish sites almost exclusively featuring small feet (I didn’t personally researched this). Women too would rather wear a smaller shoes since the size of the feet has been considered a beauty standard more unconsciously. There you have it, guys liking feet are just as natural as a guy liking the other sexualized part of the women body, although the taste is all according to the guy personal preference. On the side note, if the guy is exposed to the sexual aspect of a woman’s feet at a young age, they are more like to be sexually attracted to it in the future.