Intercourse is an act of mating and impregnation

Sexuality is about the act of mating. Humans do not have sex simply in order to reproduce. We also have sex to enjoy pleasure (recreation) and intimacy, which creates the emotional bonding that keeps couples committed to each other over the years needed to support a family (deferred reproduction).

For most animals, a male fertilises a female by making a quick insertion. Only mammals employ an extended thrusting technique. There is no obvious advantage to the extra time male mammals take to mate. This inefficiency is no doubt due to the pleasure the male obtains from thrusting and possibly also to the increase in the human brain’s imaginative capacities.

Intercourse refers to interaction between two or more people e.g. social intercourse. To have sexual intercourse means to engage in sexual activity with a lover (as opposed to masturbatory activity alone). Both ‘to have sex’ and ‘to have sexual intercourse’ often refer to vaginal intercourse. To avoid any confusion, the more specific term ‘coitus’ may be used for intercourse.

Sexual activity that involves being the receiver of an erect penis (into the mouth, vagina or anus) is inherently more risky for the receiver. When a man inserts his erect penis into another person’s orifice, he does not have his body invaded in the same way. Fellatio cannot be taken by force because of the threat of the receiver’s teeth. But both vaginal and anal intercourse can be an act of violation because a person’s anus or vagina is easily penetrated by an erect penis. The penetrating male has the pleasure of penetrating and ejaculating into an orifice. Anticipation of this pleasure (that women can never experience) is what we call male sex drive. For the receiver, any form of penetration involves providing rather than receiving pleasure.

We can differentiate between three distinct categories of sexual activity. First there are manual contacts where we use our hands (or fingers) to stimulate (massage) the sex organ (called masturbation). Masturbation can be used with a lover but less commonly to the point of orgasm. Any activity short of intercourse used to be called petting and was popular in the days before the availability of reliable contraception. A man’s optimal sexual release is obtained through thrusting to ejaculation, so intercourse typically concludes heterosexual activity. Some men enjoy extending their arousal by engaging in non-coital activities prior to intercourse. Hence the term: foreplay.

Secondly there are oral contacts where we use our mouth or tongue to kiss or stimulate (by licking, sucking or kissing) the sex organ (called oral sex) or other parts of the body. Oral sex performed on a man (called fellatio) is much more common than oral sex performed on a woman (called cunnilingus). Cunnilingus is associated with lesbians and pornography.

Thirdly there are genital contacts where a man penetrates a lover’s body (called intercourse or penetrative sex) with an erect penis. Vaginal intercourse involves a man’s erect penis penetrating a woman’s vagina. Heterosexuals and, more commonly, homosexual men also engage in anal intercourse (also called anal sex) where an erect penis penetrates a lover’s anus. Anyone may use a dildo or vibrator to penetrate a lover’s vagina or anus. Women can use a strap-on dildo to penetrate a lover (called pegging).

In the presence of an attractive potential partner, men accumulate sexual tension as a result of constant arousal. This pressure can be released by masturbation but ultimately relies on penetrative sex. Intercourse is an act that requires the penetrating male to be aroused (erect) but not the receiver. If women were consciously aroused (as men are) they would focus on the clitoris. This would work against reproduction, which relies on a penis ejaculating into a vagina. For this reason women are not aroused as men are.

We can differentiate between three approaches to intercourse. The vast majority of intercourse is defined by a man’s sex drive. A man holds his erect penis between his lover’s legs to find the entrance to her vagina. The man then thrusts rhythmically into her vagina as the woman kisses or caresses him allowing him the time he needs to ejaculate. Vaginal intercourse provides women with almost no physical stimulation or erotic arousal. Women offer intercourse to a lover because it involves them in very little explicit sexual activity and because they know that it is expected. Compared with foreplay, vaginal intercourse involves a woman in much less effort. A woman only needs to allow a man to penetrate her vagina and thrust until ejaculation.

Secondly there is intercourse that is preceded by foreplay. Foreplay is primarily provided by the man. Research indicates that men with a creative imagination tend to enjoy eroticism, fantasy, masturbation and foreplay more than others. Men’s enjoyment of eroticism (male turn-ons) may be the result of having an active creative imagination. Other men (especially when young) prefer to get straight to intercourse rather than spend time on erotic turn-ons. Eroticism is defined by male turn-ons that fall short of coitus itself.

Thirdly there is fantasy-style sex as portrayed in erotic fiction that is characterised by the proactive role of the woman. The woman initiates sexual activity, encourages the man to stimulate her and provides facial expressions and vocals that assist with male orgasm. Some women feel obligated to provide at least some of this performance for a lover either because they think it is expected or because they want a more proactive role.

It is the constant complaint of married females that their husbands are … primarily concerned with genital stimulation … It is the constant complaint of the married male that his wife … does not tactilely stimulate his genitalia. (Alfred Kinsey)

Excerpt from Learn About Sexuality (ISBN 978-0956-894748)