It may be considered taboo or unnatural, and is a criminal offense in some countries, punishable by corporal or capital punishment. This is commonly due to prohibitions against anal sex among males or teachings about the procreative purpose of sexual activity. It is controversial in various cultures, especially with regard to religious prohibitions. Strong views are often expressed about anal sex. Anal sex without protection of a condom is considered the riskiest form of sexual activity, and therefore health authorities such as the World Health Organization (WHO) recommend safe sex practices for anal sex. The anal and rectal tissues are delicate and do not provide lubrication like the vagina does, so they can easily tear and permit disease transmission, especially if a personal lubricant is not used. Anal sex is considered a high-risk sexual practice because of the vulnerability of the anus and rectum. Īs with most forms of sexual activity, anal sex participants risk contracting sexually transmitted infections (STIs). However, people may also find anal sex painful, sometimes extremely so, which may be due to psychological factors in some cases. 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 of the vagina (sometimes called the G-spot) in women, and other sensory nerves (especially the pudendal nerve). Types of anal sex can also be a part of lesbian sexual practices. While anal sex is commonly associated with male homosexuality, research shows that not all gay men engage in anal sex and that it is not uncommon in heterosexual relationships. 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. Other forms of anal sex include fingering, the use of sex toys for anal penetration, oral sex performed on the anus ( anilingus), and pegging. Anal sex or anal intercourse is generally the insertion and thrusting of the erect penis into a person's anus, or anus and rectum, for sexual pleasure.