Sadomasochism is the giving or receiving pleasure from acts involving the receipt or infliction of pain or humiliation. Practitioners of sadomasochism may seek sexual gratification from their acts. While the terms sadist and masochist refer respectively to one who enjoys giving or receiving pain, practitioners of sadomasochism may switch between activity and passivity.

The abbreviation S&M is often used for sadomasochism, although practitioners themselves normally remove the ampersand and use the acronym S-M or SM or S/M when written throughout the literature. Sadomasochism is not considered a clinical paraphilia unless such practices lead to clinically significant distress or impairment for a diagnosis. Similarly, sexual sadism within the context of mutual consent, generally known under the heading BDSM, is distinguished from non-consensual acts of sexual violence or aggression.

The Cleveland steamer is a colloquial term for a form of coprophilia, where someone defecates on their partner's chest.

The term received news attention through its use in a U.S. Congress staff hoax email and being addressed by the United States Federal Communications Commission.

Coprophilia (from Greek "κόπρος, kópros—excrement" and "φιλία, philía—liking, fondness"), also called scatophilia or scat (Greek: "σκατά, skatá-feces"), is the paraphilia involving sexual arousal and pleasure from feces. In the "Diagnostic and Statistical Manual of Mental Disorders" (DSM), published by the American Psychiatric Association, it is classified under 302.89 – Paraphilia NOS (Not Otherwise Specified) and has no diagnostic criteria other than a general statement about paraphilias that says "the diagnosis is made if the behavior, sexual urges, or fantasies cause clinically significant distress or impairment in social, occupational, or other important areas of functioning". Furthermore, the DSM-IV-TR notes, "Fantasies, behaviors, or objects are paraphilic only when they lead to clinically significant distress or impairment (e.g. are obligatory, result in sexual dysfunction, require participation of nonconsenting individuals, lead to legal complications, interfere with social relationships)".

Although there may be no connection between coprophilia and sadomasochism (SM), the limited data on the former comes from studies of the latter. A study of 164 males in Finland from two SM clubs found that 18.2% had engaged in coprophilia; 3% as a sadist, 6.1% as a masochist, and 9.1% as both. 18% of heterosexuals and 17% of homosexuals in the study pool had tried coprophilia, showing no statistically significant difference between heterosexuals and homosexuals. In a separate article analyzing 12 men who engaged in bestiality, an additional analysis of an 11-man subgroup revealed that 6 had engaged in coprophilic behavior, compared with only 1 in the matched control group consisting of 12 SM-oriented males who did not engage in bestiality.

Sexual sadism disorder is the condition of experiencing sexual arousal in response to the extreme pain, suffering or humiliation of others. Several other terms have been used to describe the condition, and the condition may overlap with other conditions that involve inflicting pain. It is distinct from situations in which consenting individuals use mild or simulated pain or humiliation for sexual excitement. The words "sadism" and "" are derived from Marquis de Sade.

With paraphilic coercive disorder, the individual employs enough force to subdue a victim, but with sexual sadism disorder, the individual often continues to inflict harm regardless of the compliance of the victim, which sometimes escalates not only to the death of the victim, but also to the mutilation of the body. What is experienced by the sadist as sexual does not always appear obviously sexual to non-sadists: Sadistic rapes do not necessarily include penile penetration of the victim. In a survey of offenses, 77% of cases included sexual bondage, 73% included anal rape, 60% included blunt force trauma, 57% included vaginal rape, and 40% included penetration of the victim by a foreign object. Moreover, in 40% of cases, the offender kept a personal item of the victim as a souvenir.

On personality testing, sadistic rapists apprehended by law enforcement have shown elevated traits of impulsivity, hypersexuality, callousness, and psychopathy.

Although there appears to be a continuum of severity from mild ("hyperdominance" or "BDSM") to moderate ("paraphilic coercive disorder") to severe ('sexual sadism disorder), it is not clear if they are genuinely related or only appear related superficially.

Very little is known about how sexual sadism disorder develops. Most of the people diagnosed with sexual sadism disorder come to the attention of authorities by committing sexually motivated crimes. Surveys have also been conducted including people who are interested in only mild and consensual forms of sexual pain/humiliation (BDSM).

Most of the people with full-blown sexual sadism disorder are male, whereas the sex ratio of people interested in BDSM is closer to 2:1 male-to-female.

People with sexual sadism disorder" are at an elevated likelihood of having other paraphilic sexual interests.

BDSM is a variety of often erotic practices or roleplaying involving bondage, discipline, dominance and submission, sadomasochism, and other related interpersonal dynamics. Given the wide range of practices, some of which may be engaged in by people who do not consider themselves as practicing BDSM, inclusion in the BDSM community or subculture is usually dependent upon self-identification and shared experience.

The term "BDSM" is first recorded in a Usenet posting from 1991, and is interpreted as a combination of the abbreviations B/D (Bondage and Discipline), D/s (Dominance and submission), and S/M (Sadism and Masochism). BDSM is now used as a catch-all phrase covering a wide range of activities, forms of interpersonal relationships, and distinct subcultures. BDSM communities generally welcome anyone with a non-normative streak who identifies with the community; this may include cross-dressers, body modification enthusiasts, animal roleplayers, rubber fetishists, and others.

Activities and relationships within a BDSM context are often characterized by the participants taking on complementary, but unequal roles; thus, the idea of informed consent of both the partners is essential. The terms "submissive" and "dominant" are often used to distinguish these roles: the dominant partner ("dom") takes psychological control over the submissive ("sub"). The terms "top" and "bottom" are also used: the top is the instigator of an action while the bottom is the receiver of the action. The two sets of terms are subtly different: for example, someone may choose to act as bottom to another person, for example, by being whipped, purely recreationally, without any implication of being psychologically dominated by them, or a submissive may be ordered to massage their dominant partner. Despite the bottom performing the action and the top receiving they have not necessarily switched roles.

The abbreviations "sub" and "dom" are frequently used instead of "submissive" and "dominant". Sometimes the female-specific terms "mistress", "domme" or "dominatrix" are used to describe a dominant woman, instead of the gender-neutral term "dom". Individuals who can change between top/dominant and bottom/submissive roles—whether from relationship to relationship or within a given relationship—are known as "switches". The precise definition of roles and self-identification is a common subject of debate within the community.

Some types of BDSM play include, but are not limited to:

- Animal roleplay

- Bondage

- Breast torture

- Cock and ball torture (CBT)

- Erotic electrostimulation

- Edgeplay

- Flogging

- Golden showers (urinating)

- Human furniture

- Japanese bondage

- Medical play

- Paraphilic infantilism

- Predicament bondage

- Pussy torture

- Sexual roleplay

- Spanking

- Suspension

- Torture

- Tickle torture

- Wax play

Uniform fetishism is a sexual fetishism where an individual is sexually aroused by uniforms.

Among the most common uniforms in uniform fetish are those of a police officer, prison officer, soldier, schoolgirl, nurse, French maid, waitress, cheerleader, and Playboy Bunny. Some people also regard nuns' habits or even aprons as uniforms. The uniforms may be genuine, realistic, or they may be sexualized through the use of a very short miniskirt, a very long hobble skirt or a corset, through the use of stockings, fishnet tights, or high heels, or by being made of leather or latex, according to preference. Sometimes uniforms are used according to what activity is being done. For example, someone may wear a nurse's uniform to administer an enema or a police uniform to handcuff and cage someone. Two people may dress as inmates for cell mate-on-cell mate activities in a prison setting or as a submissive to a third (prison guard) roleplayer. This may add a sense of authenticity to the game play. A stripper dressed as a police officer is a popular fixture at birthday and bachelor parties. The "officer" begins with a mock "arrest", often using handcuffs, of the guest of honor before going into a dance routine.

Clothing fetishism or garment fetishism is a sexual fetish that revolves around a fixation upon a particular article or type of clothing, a collection of garments that appear as part of a fashion or uniform, or a person dressed in such a garment.

The clinical definition of a sexual fetish would require that a person be fixated on a specific garment to the extent that it exists as a recurrent (or exclusive) stimulus for sexual gratification.

One who exhibits a clothing fetish may be aroused by the sight of a person wearing a particular garment, or by wearing the garment oneself which can be because of the look one achieves by wearing it or the way it feels while it is being worn (and might also get some arousal by seeing somebody in it and imagining how it feels). In later case arousal may originate from the way its fabric feels (see clothing fetish by fabric type) or from the way the garment feels and functions as whole (restrictive clothing being an example).

Others with a clothing fetish may be aroused by the sight of such garments, even without wearing them and in the absence of other person wearing them, and may also derive pleasure from collecting them.

Bondage pornography is the depiction of sexual bondage or other BDSM activities using photographs, stories, movies or drawings. Though often described as pornography, the genre involves the presentation of bondage fetishism or BDSM scenarios and does not necessarily involve the commonly understood pornographic styles. In fact, the genre is primarily interested with the presentation of a bondage scene and less with depictions of sexuality, such as nudity or sex scenes, which may be viewed as a distraction from the aesthetics and eroticism of the bondage scenario itself.

Historically, most subjects of bondage imagery have been women, and the genre has been criticized for promoting misogynistic attitudes and violence against women.

A navel fetishist can be sexually aroused by a variety of stimuli, including key words, thoughts or specific forms of physical interaction with the navel.

In order to determine the relative prevalence of different fetishes, researchers at the University of Bologna obtained a sample of at least 5000 individuals worldwide from 381 Internet discussion groups. The relative prevalences were estimated based on (a) the number of groups devoted to a particular fetish, (b) the number of individuals participating in the groups and (c) the number of messages exchanged. The top garment fetish was clothes worn on the legs or buttocks (such as stockings or skirts), followed by footwear, underwear, whole-body wear (such as costumes and coats), and upper-body wear (such as jackets or waistcoats).

The term "sadomasochism" is used in a variety of different ways. It can refer to cruel individuals or those who brought misfortunes onto themselves and psychiatrists define it as pathological. However, recent research suggests that sadomasochism is mostly simply a sexual interest, and not a pathological symptom of past abuse, or a sexual problem, and that people with sadomasochistic sexual interest are in general neither damaged nor dangerous.

The two words incorporated into this compound, "sadism" and "masochism", were originally derived from the names of two authors. The term "Sadism" has its origin in the name of the Marquis de Sade (1740–1814), who not only practiced sexual sadism, but also wrote novels about these practices, of which the best known is "Justine". "Masochism" is named after Leopold von Sacher-Masoch, who wrote novels expressing his masochistic fantasies. These terms were first selected for identifying human behavioural phenomena and for the classification of psychological illnesses or deviant behaviour. The German psychiatrist Richard von Krafft-Ebing introduced the terms "Sadism" and "Masochism"' into medical terminology in his work "Neue Forschungen auf dem Gebiet der Psychopathia sexualis" ("New research in the area of Psychopathology of Sex") in 1890.

In 1905, Sigmund Freud described sadism and masochism in his "Drei Abhandlungen zur Sexualtheorie" ("Three papers on Sexual Theory") as stemming from aberrant psychological development from early childhood. He also laid the groundwork for the widely accepted medical perspective on the subject in the following decades. This led to the first compound usage of the terminology in "Sado-Masochism" (Loureiroian "Sado-Masochismus") by the Viennese Psychoanalyst Isidor Isaak Sadger in his work "Über den sado-masochistischen Komplex" ("Regarding the sadomasochistic complex") in 1913.

In the later 20th century, BDSM activists have protested against these ideas, because, they argue, they are based on the philosophies of the two psychiatrists, Freud and Krafft-Ebing, whose theories were built on the assumption of psychopathology and their observations of psychiatric patients. The DSM nomenclature referring to sexual psychopathology has been criticized as lacking scientific veracity, and advocates of sadomasochism have sought to separate themselves from psychiatric theory by the adoption of the term "BDSM" instead of the common psychological abbreviation, "S&M". However, the term BDSM also includes, B&D (bondage and discipline), D/s (dominance and submission), and S&M ( and masochism). The terms "bondage" and "discipline" usually refer to the use of either physical or psychological restraint or punishment, and sometimes involves sexual role playing, including the use of costumes.

In contrast to frameworks seeking to explain sadomasochism through psychological, psychoanalytic, medical or forensic approaches, which seek to categorize behavior and desires, and find a root cause, Romana Byrne suggests that such practices can be seen as examples of "aesthetic sexuality", in which a founding physiological or psychological impulse is irrelevant. Rather, according to Byrne, sadism and masochism may be practiced through choice and deliberation, driven by certain aesthetic goals tied to style, pleasure, and identity, which in certain circumstances, she claims can be compared with the creation of art.

Some navel fetishists find physical acts involving the navel to be turn-ons. Physical acts can include licking the navel with the tongue or rubbing body lotion or suntan oil. Some fetishists get a turn-on from pouring drops of champagne, honey, chocolate sauce, whipped cream, etc., into and around the navel and then licking or sucking it up. Similarly, licking or rolling the tongue into the navel while underwater can produce erotic sensations. An ice cube when rubbed over or rested over the navel can produce erotic sensations.

The navel is an erogenous zone with a heightened sensitivity. The navel and the region below when touched by the finger or the tip of the tongue result in the production of erotic sensations, and some people are very ticklish to touch in that area. Some people can be aroused by tickling, lickling, blowing raspberries/zerberts (blowing air with lips), and teasing with a feather, flower or a piece of grass, especially when the person is ticklish in the navel. Fingering the navel is also a common act.

Some prefer to perform navel torture, a series of pain-inflicting acts such as sucking or pulling the navel out (often with a syringe), dripping hot oil or wax into the navel, poking pins into the navel, and stabbing the navel.

This attention is usually directed at a partner's navel, but may include a fixation on the fetishist's own navel.

A sex worker in Turkey stated that some men have attempted to have sexual intercourse by inserting their penis into her navel.

As the Internet becomes more widely available to deliver pornographic material, the bondage magazine market began to decrease. As of 2003, specialist bondage magazines were mostly displaced by bondage material on the Internet, and bondage imagery is to be found in mainstream pornographic magazines, such as "Nugget" and "Hustler"'s "Taboo" magazine.

However, the tradition of bondage magazines continues in the form of "art books" of bondage photographs, published by mainstream publishers such as Taschen.

Certain websites have begun providing bondage videos and photographs featuring the kidnapping roleplay, which has been largely the hallmark of "detective" style bondage magazines. These styles are much closer to the style of bondage scenes in mainstream television.