A sexual cue
A female’s feet can be seen as a sexual cue. The person’s mind might use his imagination to imagine further sexual things related to the feet, and as a result, the person might like them.
Bare feet is seen during sex
As bare feet are usually seen during sex, they can remind a person of sex or motivate them to think about sex.
The brain is wired to like them
According to many psychologists, the male brain is actually wired to get attracted to feet. The level of attraction, however, differs from a man to another. (See Study: Male and female Brains Operate Differently at a Molecular Level)
A small feet looks more feminine
According to research, men tend to like women with smaller feet as they seem more feminine. Seeing small feet might thus trigger a man’s sexual desire.
They have a foot fetish
In some extreme cases, a man could have a certain foot fetish or an intense and unusual attraction to women’s feet. (See Why do women love high heels?)
The feet can be seen when a woman is nude or wearing a swimsuit. These associations can make some men find their feet more attractive as they remind them of those other situations.
Positive childhood memories
According to one theory, the positive childhood memories a child had when he was near his mother’s feet could have made feet a symbol of safety and security.
Some research says that the smell of feet can be arousing to some men. This can act like natural pheromones.
According to one theory, the natural curves of a woman’s feet can make them sexually arousing to men.
Women care about their feet
Because women usually care about making their feet beautiful, unlike men, men can find them attractive.
The feet and sexual areas are connected
The neurons responsible for the sensations we get in the feet are close to the neurons responsible for sexual areas in the brain. According to one theory, this makes feet more erotic.
The feet lead to the legs
As the foot is connected to the leg, it can make men think more about the leg and, as a result, finds both the leg and the feet attractive.
They can signal fertility
Men are wired to look for fertile women. Healthy-looking feminine feet can give a man an indication that this woman is fertile.