The term combines elements of the Freudian psychoanalytic fetish and the Marxist commodity fetish, and is used in the context of British, Spanish and French colonialism and imperialism and their aftereffects. The Silent Duck, also called Duck-Billing, is the technique often used in which the person engaging in hand insertion shapes the hand to resemble a duck beak. The term sadomasochism is derived from the words momsex sadism and masochism . Sub-genres can also be classified into the characteristics of the performers or the type of sexual activity on which it concentrates, and not necessarily on the market to which each sub-genre appeals. The name was coined from the title of the controversial book. The range of its individual characteristics is thereby wide. There are number of types of sex parties: Swinger party/gathering A swinger party or partner-swapping party is a gathering at which individuals or couples in a committed relationship can engage in sexual activities with others as a recreational or social activity. When used as an alternative to penile-vaginal penetration, the goal may be to preserve virginity or to prevent pregnancy. Reality pornography is professionally made porn which seeks to emulate the style of amateur pornography. It is sometimes combined with BDSM features. For some people, non-penetrative sex is the primary sexual activity of choice above all others. The phrase buttered bun is sometimes used to refer to the owner of the orifice in question. Tentacle erotica can be consensual, but frequently hentai movies contains elements of non-consensual sex. Jerk off instruction features a performer encouraging or instructing the viewer to masturbate, often culminating in a countdown at the end of which the viewer is invited to induce orgasm. The object or situation of interest is called the fetish; the person who has young gay porn a fetish for that object/situation is a fetishist. Gay-for-pay describes male or female actors, pornographic stars, or sex workers who self-identify as heterosexual but who are paid to act or perform as homosexual professionally.