Sexual intercourse

Sexual intercourse (or coitus or copulation) is principally the insertion and thrusting of the penis, usually when erect, into the vagina for sexual pleasure, reproduction, or both. This is also known as vaginal intercourse or vaginal sex. Other forms of penetrative sexual intercourse include anal sex (penetration of the anus by the penis), oral sex (penetration of the mouth by the penis or oral penetration of the female genitalia), fingering (sexual penetration by the fingers), and penetration by use of a dildo (especially a strap-on dildo). These activities involve physical intimacy between two or more individuals and are usually used among humans solely for physical or emotional pleasure and can contribute to human bonding. There are different views on what constitutes sexual intercourse or other sexual activity, which can impact on views on sexual health. Although sexual intercourse, particularly the variant coitus, generally denotes penile–vaginal penetration and the possibility of creating offspring, it also commonly denotes penetrative oral sex and penile–anal sex, especially the latter. It usually encompasses sexual penetration, while non-penetrative sex has been labeled 'outercourse', but non-penetrative sex may also be considered sexual intercourse. Sex, often a shorthand for sexual intercourse, can mean any form of sexual activity. Because people can be at risk of contracting sexually transmitted infections during these activities, safe sex practices are advised, although transmission risk is significantly reduced during non-penetrative sex. Various jurisdictions have placed restrictive laws against certain sexual acts, such as incest, sexual activity with minors, prostitution, rape, zoophilia, sodomy, premarital and extramarital sex. Religious beliefs also play a role in personal decisions about sexual intercourse or other sexual activity, such as decisions about virginity, or legal and public policy matters. Religious views on sexuality vary significantly between different religions and sects of the same religion, though there are common themes, such as prohibition of adultery. Reproductive sexual intercourse between non-human animals is more often called copulation, and sperm may be introduced into the female's reproductive tract in non-vaginal ways among the animals, such as by cloacal copulation. For most non-human mammals, mating and copulation occur at the point of estrus (the most fertile period of time in the female's reproductive cycle), which increases the chances of successful impregnation. However, bonobos, dolphins and chimpanzees are known to engage in sexual intercourse regardless of whether or not the female is in estrus, and to engage in sex acts with same-sex partners. Like humans engaging in sexual activity primarily for pleasure, this behavior in these animals is also presumed to be for pleasure, and a contributing factor to strengthening their social bonds. Sexual intercourse may be called coitus, copulation, coition, or intercourse (the last of which is typically shorthand for sexual intercourse). Coitus is derived from the Latin word coitio or coire, meaning 'a coming together or joining together' or 'to go together', and is known under different ancient Latin names for a variety of sexual activities, but usually denotes penile–vaginal penetration. This is often called vaginal intercourse or vaginal sex. Vaginal sex, and less often vaginal intercourse, may also denote any vaginal sexual activity, particularly if penetrative, including sexual activity between lesbian couples. Copulation, by contrast, more often denotes the mating process, especially for non-human animals; it can mean a variety of sexual activities between opposite-sex or same-sex pairings, but generally means the sexually reproductive act of transferring sperm from a male to a female or sexual procreation between a man and a woman. Although sexual intercourse, sex and 'having sex' also most commonly denote penile–vaginal intercourse, sex can be significantly broad in its meaning and may cover any penetrative or non-penetrative sexual activity between two or more people. The World Health Organization (WHO) states that non-English languages and cultures use different words for sexual activity, 'with slightly different meanings'. Various vulgarisms, slang, and euphemisms are used for sexual intercourse or other sexual activity, such as fuck, shag, and the phrase 'sleep together'. The laws of some countries use the euphemism 'carnal knowledge.' Penetration of the vagina by the erect penis is additionally known as intromission, or by the Latin name immissio penis (Latin for 'insertion of the penis'). The age of first sexual intercourse is called sexarche. Vaginal, anal and oral sex are recognized as sexual intercourse more often than other sexual behaviors. While non-penetrative and non-penile–vaginal sexual activities may be regarded as sexual intercourse, they might alternatively be considered a means of maintaining virginity (sometimes called 'technical virginity)' or labeled 'outercourse', regardless of any penetrative aspects, which is more often the case for oral sex than for anal sex. Virginity loss is often based on penile–vaginal intercourse partly because heterosexual couples may engage in anal or oral sex not only for sexual pleasure, but additionally as a way of maintaining that they are virgins if they have not engaged in the reproductive act of coitus. Some gay men consider frotting or oral sex as a way of maintaining their virginities, with penile-anal penetration used as sexual intercourse and for virginity loss, while other gay men may consider frotting or oral sex as their main forms of sexual activity. Lesbians may categorize oral sex or fingering as sexual intercourse and subsequently an act of virginity loss, or tribadism as a primary form of sexual activity. Researchers commonly use sexual intercourse to denote penile–vaginal intercourse while using specific words, such as anal sex or oral sex, for other sexual behaviors. Scholars Richard M. Lerner and Laurence Steinberg state that researchers also 'rarely disclose' how they conceptualize sex 'or even whether they resolved potential discrepancies' in conceptualizations of sex. Lerner and Steinberg attribute researchers' focus on penile–vaginal sex to 'the larger culture's preoccupation with this form of sexual activity,' and have expressed concern that the 'widespread, unquestioned equation of penile–vaginal intercourse with sex reflects a failure to examine systematically 'whether the respondent's understanding of the question matches what the researcher had in mind''. This focus can also relegate other forms of mutual sexual activity to foreplay or contribute to them not being regarded as 'real sex', and limits the meaning of rape. It may also be that conceptually conflating sexual activity with vaginal intercourse and sexual function hinders and limits information about sexual behavior that non-heterosexual people may be engaging in, or information about heterosexuals who may be engaging in non–vaginal sexual activity.