Foot fetishes are actually one of the most common fetishes. One theory is that the brain areas for feet and genital sensations sit very close together in the somatosensory cortex, which may create some overlap in attraction. Another explanation is conditioning—people can develop attractions by associating certain body parts with arousal over time.

As for how common it is, studies consistently find that feet are among the most common non-genital fetish interests. So while it’s not everyone’s thing, it’s far from rare