Anal sex

Anatomy and stimulation

The anal region and rectum contain many nerve endings, making anal sex potentially pleasurable for both men and women. The internal and external sphincter muscles, which control the opening and closing of the anus, are sensitive membranes with numerous nerve endings that can facilitate either pleasure or pain. The inner third of the anal canal is less sensitive to touch than the outer two-thirds but responds more to pressure, while the rectum is a curved tube about 8 or 9 inches long with the capacity to expand. Anal sex occurs less frequently than other sexual behaviors, but its associations with dominance, submission, and taboo make it appealing across sexual orientations.

Activities include use of sex toys such as dildos, butt plugs, or anal beads, as well as anal fingering, anilingus, pegging, anal masturbation, figging, and fisting. Fisting is among the least practiced activities because few people can relax enough to accommodate a fist. For male receptive partners, anal penetration can stimulate the prostate through the anal wall, potentially producing pleasurable sensations and orgasm. Prostate stimulation may yield a deeper, more intense orgasm than penile stimulation alone, though many men do not reach orgasm solely from receptive anal sex.

Male to female

The anal sphincters are typically tighter than the vaginal pelvic muscles, which can enhance pleasure for the inserting male during male-to-female anal intercourse due to the pressure on the penis. Men may also enjoy the penetrative role because of its association with dominance, its forbidden allure, or because it offers an additional option for penetration. Some women find receptive anal intercourse painful or uncomfortable and may engage only to please a male partner, while others find it pleasurable or prefer it to vaginal intercourse.

For some heterosexuals, anal intercourse is considered exotic, pleasurable, exciting, and possibly more intimate than vaginal sex. Anal intercourse is sometimes used as a substitute for vaginal intercourse during menstruation. Pregnancy is greatly reduced during anal sex, though it can still occur if sperm reaches the vaginal opening.

Some couples practice anal sex as contraception, often without a condom. In some Christian communities in the United States, couples may engage in anal sex to preserve female virginity, as it does not tear the hymen and is non-procreative. This practice is sometimes called technical virginity.

Health risks

Anal sex poses two principal dangers: infections from microorganisms not found elsewhere on the body, and physical damage to the fragile anus and rectum. Unprotected penile-anal penetration, called barebacking, carries a higher risk of transmitting sexually transmitted infections because the anal sphincter is delicate and easily torn, providing an entry for pathogens. Using condoms, ample lubrication, and safer sex practices reduce the risk of STIs.

Condoms can break or come off more easily during anal sex due to the tightness of the anal sphincters during friction. Individual penis size is rarely mentioned in scientific literature regarding stretching or injury risk. Unprotected receptive anal sex with an HIV-positive partner is the sex act most likely to result in HIV transmission. People without sound knowledge of sexual risks are susceptible to STIs.

Because some view anal sex as not "real sex" and believe it does not result in virginity loss or pregnancy, teenagers and young people may consider vaginal intercourse riskier and may think STIs only result from vaginal intercourse. Condom use during anal sex is often reported to be low and inconsistent across groups in various countries. Although anal sex alone does not lead to pregnancy, pregnancy can still occur if sperm is deposited near the vagina's entrance and travels along lubricating fluids, or if sperm is transported to the vaginal opening by fingers or other body parts.

Cultural views

Different cultures have held varying views on anal sex throughout history, with some being more positive than others. Historically, anal sex has been restricted or condemned, especially based on religious beliefs, and has commonly been used as a form of domination, with the penetrating partner representing masculinity and the receptive partner representing femininity. Many cultures have recorded the practice of anal sex between males, which has been especially stigmatized or punished; in some societies, those discovered engaging in it were put to death by decapitation, burning, or mutilation. In modern times, anal sex has become more accepted and is often considered a natural, pleasurable form of sexual expression, with the buttocks and anus becoming more eroticized in culture and pornography.

However, engaging in anal sex is still punished in some societies; for example, Iran's Penal Code states that both men involved in same-sex penetrative or non-penetrative sex will be punished, and those convicted of anal sex will be executed at the judge's discretion. The ancient Sumerians had relaxed attitudes toward sex and did not regard anal sex as taboo. Entu priestesses, forbidden from producing offspring, frequently engaged in anal sex as birth control. Sumerian texts refer to homosexual anal intercourse, and the gala priests, who worked in temples of the goddess Inanna, were known for their homosexual proclivities; the Sumerian sign for gala was a ligature of the signs for 'penis' and 'anus'.