Found here: https://answers.yahoo.com/question/index?qid=20120120002507AAwZHcs

Author: Roger

To fetishize something is to give it sexual power or valence, Many men find the breasts and buttocks of women (or men, if they are homosexually inclined) sexually arousing, and since our culture sees this interest as common, it isn’t considered strange. In other cultures, other parts of the body are found to be stimulating; in some African groups a woman’s breasts have little power to excite but the inside of the thigh is considered powerfully sexual.

Foot fetishism, in which a partner’s feet excite, is the commonest of the unusual sexual arousal areas. Your question is, perhaps, how can feet, which to most people have no romantic or sexual associations, be stimulating? The answer must involve the fetishist’s psychosexual development. Since feet are usually covered, they have some of the allure of body parts not usually exposed, but more than simple looking is involved. There is an element of the outré, the forbidden, the bizarre that comes into play. That is to say, the strangeness of the notion is itself a stimulus, the way some people find odd behavior in sex arousing.

Moreover, foot fetishism is a stimulus that comes partly at the expense of dealing with more conventionally and directly sexual parts of the body–vagina / penis, breasts, buttocks. A foot fetish, in some individuals who have sexual urges but feel uncomfortable with them, may be both safe and dangerous: safe because the desire is transferred to a non-threatening part of the body (a foot fetishist does not have to worry about the usual kind of sexual performance) and dangerous since feet readily respond to touch–they are ticklish and are sensitive to the degree, if not in the usual way, that sexual areas are sensitive. In this way conventional sex, which the fetishist finds scary, is both avoided and confronted, engaged with and not engaged with simultaneously. It keeps the fetishist “safe” while allowing release.

Of course, other areas of the body could also be fetishized.

Persons who find urinating and defecating stimulating are probably more deeply stressed than foot fetishists. Since sexual activity occurs in the regions of the body also responsible for micturating and voiding, the two are, in early childhood, associated. Most adults separate erotic feeling and voiding the bowels or bladder, seeing the former as sexual and other as merely functional and of little emotional interest. For a young child, controlling feces and urine are part of emotional development; mastery over them is a sign of maturity. However, some adults, for reasons connected to their early treatment and consequent development, do not make this distinction; for them urinating and defecating retain emotional power.

This is as far as I can figure. Some of what I have written comes from thinking about these matters independently but for the paragraph about urinating and defecating, I thought about a study I read of Adolf Hitler by Walter C. Langer. Hitler found being defecated on sexually stimulating; according to Langer in his youngest years Hitler’s parents treated him in such an way that emotionally he was unable to accept the physical facts about birth and sexual relations and thought, in a primitive childish way, that babies were born through the anus. Obviously, in Hitler’s case these confusions and arrested development expressed themselves in ways that had consequences beyond simply his own psychological case history.

Sorry this was so long. I wrote it partly to think about these issues myself.

via Can someone please explain feet,toilet (pee and poop) fetishes?.

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