I'm assuming that part of the reason you're thinking about this is because of the Chinese practice of footbinding. If so, the first point I would make is that footbinding was a) not a practice in ancient China. While the definition of what's considered "the antiquities" of China can sometimes be nebulous (and the tripartite division of history of antiquities-medieval-modern doesn't really suit China) what we do know is that the practice of footbinding did not become commonplace till the Southern Song, which would be considered "medieval" if anything, and certainly not ancient. B) I'd also point out that it was a Han ethnic group practice, and was not practised by the Mongol ruling elite during the Yuan dynasty, nor the Manchus during the Qing dynasty, or by the other ethnic minorities that lived in China at the time.

While it's hard to generalise over a very long period of time, to my knowledge, women's feet weren't ever primarily bound for sexual reasons. Foot binding was done primarily for marital reasons; a Han woman without her feet bound would have little hope of achieving an advantageous marriage and bound feet also represented something that separated the Han from the non-Han. Thus, those without bound feet were seen as barbaric while those with bound feet were seen as civilised. While there was a sense of eroticism attached to women's bound feet and there was sexual material written about the mystique of the bound foot, it's important to emphasise that this was with regards to bound feet and not feet in general.

So why am I putting such emphasis on talking about bound feet? The simple reason is that it was the bound foot that was seen as private. While Han girls would hide their feet and would never show their feet to others, other women would walk around unshod without covering their feet during the Qing dynasty and the feet of females from other ethnic groups were not seen as erotic or private, though body parts such as the vagina or the breasts would be comparatively seen as still private. Hence, the male foot would not have been seen in the same light as the feminine bound foot, in some ways similar to how we in modern society see the nipple as a sexual thing for women, but don't for men.