ANAL SEX: (source: wikipedia.org)

Anal sex most often refers to the sex act involving insertion of the penis into the rectum. The term anal sex can also sometimes include other sexual acts involving the anus, including but not limited to anilingus and fingering.

It is a form of sexual behavior considered to be comparatively high in risk, due to the vulnerability of the tissues and the septic nature of the anus. As the rectal mucosa provides little natural lubrication, a personal lubricant is most often required or preferred when penetrating the anus.

Anal Sex Heterosexual:

In modern Western countries anal sex is reported as being a widely practiced, if still minority, form of intercourse between men and women. In some cultures, receptive anal intercourse by heterosexual partners is widely accepted. One reason is that there is very low risk of unwanted pregnancy via unprotected anal intercourse. Also, anal sex is sometimes seen as preserving female virginity because it leaves the hymen intact. Another reason is that the anus is considered to yield more tactile pleasure for the penis, being tighter than the vagina. The Renaissance poet Pietro Aretino advocated the practice in his Sonetti Lussuriosi (Lust Sonnets).

- Pegging:

A woman using a strap-on dildo to anally penetrate a man is referred to as pegging. Due to the proximity of the prostate gland to the rectum, it has been suggested that males may achieve greater satisfaction in this manner than females.

- Anal sex and female virginity:

Though more often applied to first penetration, the concept of "technical virginity" is sometimes conceived as resting solely on vaginal penetration.

Anal Sex Homosexual

In recent decades, particularly in Western cultures, anal sex has been popularly associated with male homosexuality and men who have sex with men (MSM). Among MSM who have anal sex, the insertive partner is referred to as the top or active partner. The man being penetrated is referred to as the bottom or passive partner. Preference for either is referred to as versatile. Not all MSM engage in anal sex, and some groups such as frot advocacy groups actively denounce anal sex as degrading toward the receptive partner and an unnecessary health risk. This viewpoint cites the increased HIV risk and physiological differences of the anus from the vagina.