Edward O. Laumann's The Social Organization of Sexuality: Sexual Practices in the United States found that about 20% of heterosexuals have engaged in anal sex, and sex researcher Alfred Kinsey found that number to be closer to 40%. More recently, a researcher from the University of British Columbia (quoted in the May 5, 2005 issue of The Georgia Straight) puts the number of heterosexuals who regularly practice anal sex at between 30% and 50%.

In several cultures (such as the Mediterranean area, Middle East and Latin America) female receptive anal intercourse in a heterosexual context is widely accepted, especially as there is less risk of unwanted pregnancy via unprotected anal than unprotected vaginal intercourse. Anal sex is sometimes seen as preserving female virginity (or at least preserving an intact hymen until marriage) [citation needed].

One appeal of heterosexual anal sex may be the fact that the anus is generally tighter than the vagina. Some consider penetrating the tighter orifice to be a more pleasurable experience.

In certain contexts male-male anal intercourse among males who otherwise identify as heterosexual is seen as a temporary behaviour to which they resort when confined in single-sex environments, such as prisons or soldiers separated from partners. (See: Situational sexual behavior and Prison sex) Some men have sex with men without categorising themselves as homosexual or bisexual. These men who have sex with men (MSM) may still identify as heterosexual while engaging in same sex activity from time to time.

Down low or DL is a slang phrase used in English of the United States for "secret information," as in "What's the down-low?" or "Keep it on the down-low" (meaning "Do not make it known"). It originated in African-American slang.

Anal sex among gay/bisexual men
In modern times in Western cultures, anal sex is popularly associated with gay men, and studies (Lauman, for example) claim that about 80% of gay men in the United States have engaged in anal sex.

Not all gay/bi men regularly engage in anal sex or find it pleasurable, however. It may be that some gay/bi men try anal sex once or a few times and then rarely if ever engage in the practice, and others may never try it at all. Some may reserve it only for committed relationships. Since data on gay (or bi) sexual behavior tends to arouse such controversy, it is difficult to make solid claims in this area.

While some gay/bi male couples comprise an "active" partner and a "receptive" partner (a top and a bottom) this is not true of all gay/bi couples who practice anal sex: many gay/bi men who have anal sex both "top" and "bottom" at different times, also known as "versatile" or "switch."

Several gay slang terms are generally reserved for anal sex between two males, such as "barebacking" which refers to unprotected anal intercourse, ie. intercourse without the use of a condom.