As with most forms of sexual activity, anal sex participants risk contracting sexually transmitted infections . Partners can engage in penetrative sex, known as full swap, or choose to soft swap in which they engage only in non-penetrative sex. When all regions of the face are included, facial cum shots comprise approximately 62% of scenes where external ejaculation occurs. Foot fetishism, foot partialism, foot worship, or podophilia is a pronounced sexual interest in feet. Group sex can occur between people of all sexual orientations and genders. In some areas, there are laws stating it is not legally possible to consent to be killed, and elsewhere it may still be legally dubious . The stimulation may involve hands, fingers, everyday objects, sex toys or combinations of these. Strictly speaking, bondage means binding the partner by tying their appendages together; for example, by the use of handcuffs or by lashing their arms to an object. Failure to honor a safeword is considered serious misconduct and could even change the sexual consent situation into a crime, depending on the relevant law, since the bottom has explicitly revoked his or her consent to any actions that follow the use of the safeword . Clothed female, naked male is a genre of erotica featuring one or more nude men and one or more clothed women. An orgy is a gathering where guests freely engage in open and unrestrained sexual activity or group sex; and a bunga bunga orgy is an orgy in which participants have sex underwater, celebrity sex tape such as in a swimming pool or a hot tub. Sometimes special furniture is used, such as a queening stool or smotherbox. Sex experts have praised various techniques that the performer can use during fellatio to increase their partner pleasure. The Japanese sex industry uses the term Paizuri . Buck Angel is the best-known actor in this genre. Said that the female buttocks evolved in the context of females competing for the attention and parental commitment of powerful resource-controlling males as an honest display of fat reserves that could not be confused with another type of tissue, although T.