Anilingus in the context of Nerve

Oral sex, sometimes referred to as oral intercourse, is sexual activity involving the stimulation of the genitalia of a person by another person using the mouth (including the lips, tongue, or teeth). Cunnilingus is oral sex performed on the vulva while fellatio is oral sex performed on the penis. Anilingus, another form of oral sex, is oral stimulation of the anus.

Oral sex may be performed as foreplay to incite sexual arousal before other sexual activities (such as vaginal or anal intercourse), or as an erotic and physically intimate act in its own right. Like most forms of sexual activity, oral sex can pose a risk for contracting sexually transmitted infections (STIs). However, the transmission risk for oral sex, especially HIV transmission, is significantly lower than for vaginal or anal sex.

Anal sex or anal intercourse principally means the insertion and thrusting of the erect penis into a person's anus, or anus and rectum, for sexual pleasure. Other forms of anal sex include anal fingering, the use of sex toys, anilingus, and pegging. Although anal sex most commonly means penile–anal penetration, sources sometimes use anal intercourse to exclusively denote penile–anal penetration, and anal sex to denote any form of anal sexual activity, especially between pairings as opposed to anal masturbation.

While anal sex is commonly associated with male homosexuality, research shows that not all homosexual men engage in anal sex and that it is not uncommon in heterosexual relationships. Types of anal sex can also be part of lesbian sexual practices. People may experience pleasure from anal sex by stimulation of the anal nerve endings, and orgasm may be achieved through anal penetration – by indirect stimulation of the prostate in men, indirect stimulation of the clitoris or an area in the vagina (sometimes called the G-spot) in women, and other sensory nerves (especially the pudendal nerve). People may also find anal sex painful, sometimes extremely so, which may be due to psychological factors in some cases.

Safe sex is sexual activity using protective methods or contraceptive devices (such as condoms) to reduce the risk of transmitting or acquiring sexually transmitted infections (STIs), especially HIV. The terms safer sex and protected sex are sometimes preferred, to indicate that even highly effective prevention practices do not completely eliminate all possible risks. It is also sometimes used colloquially to describe methods aimed at preventing pregnancy that may or may not also lower STI risks.

The concept of safe sex emerged in the 1980s as a response to the global AIDS epidemic, and possibly more specifically to the AIDS crisis in the United States. Promoting safe sex is now one of the main aims of sex education and STI prevention, especially reducing new HIV infections. Safe sex is regarded as a harm reduction strategy aimed at reducing the risk of STI transmission.

A sex position is a positioning of the bodies that people use to engage in sexual intercourse or other sexual activities. Sexual acts are generally described by the positions the participants adopt in order to perform those acts. Though sexual intercourse generally involves penetration of the body of one person by another, sex positions commonly involve non-penetrative sexual activities.

Three broad and overlapping categories of sexual activity are commonly practiced: vaginal sex, anal sex, and oral sex (mouth-on-genital or mouth-on-anus). Sex acts may also be part of a fourth category, manual sex, which is stimulating the genitals or anus by using fingers or hands. Some acts may include stimulation by a device (sex toy), such as a dildo or vibrator. There are numerous sex positions that participants may adopt in any of these types of sex acts, and some authors have argued that the number of sex positions is essentially limitless.