Sexual intercourse

A penis (plural penises or penes ) is the primary sexual organ that male animals use to inseminate sexually receptive mates (usually females and hermaphrodites) during copulation.

Foreplay may precede some sexual activities, often leading to sexual arousal of the partners and resulting in the erection of the penis or natural lubrication of the vagina.

The vagina allows for sexual intercourse and birth.

There are different views on what constitutes sexual intercourse or other sexual activity, which can impact on views on sexual health.

People engage in a variety of sexual acts, ranging from activities done alone (e.g., masturbation) to acts with another person (e.g., sexual intercourse, non-penetrative sex, oral sex, etc.) in varying patterns of frequency, for a wide variety of reasons.

A strap-on dildo can be used for a wide variety of sexual activities, including vaginal sex, gay sex, oral sex, or solo or mutual masturbation.

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.

When the gametes are combined via sexual intercourse to form a fertilized egg, the resulting child will have 23 chromosomes from each parent genetically recombined into 23 chromosome pairs or 46 total.

It usually encompasses sexual penetration, while non-penetrative sex has been labeled "outercourse", but non-penetrative sex may also be considered sexual intercourse.

It generally excludes the penetrative aspects of vaginal, anal, or oral sexual activity, but includes various forms of sexual and non-sexual activity, such as frottage, mutual masturbation, kissing, or cuddling.

Various jurisdictions place restrictions on certain sexual acts, such as incest, sexual activity with minors, prostitution, rape, zoophilia, sodomy, premarital and extramarital sex.

Rape is a type of sexual assault usually involving sexual intercourse or other forms of sexual penetration carried out against a person without that person's consent.

Oral sex may be performed as foreplay to incite sexual arousal before other sexual activities (such as vaginal or anal intercourse), or as an erotic and physically intimate act in its own right.

Some include penis-shaped items clearly designed for vaginal penetration, even if they are not true approximations of a penis.

The pelvic thrust is used during sexual intercourse by many species of mammals, including humans, or for other sexual activities (such as non-penetrative sex).

Fuck is a profane English-language word which often refers to the act of sexual intercourse but is also commonly used as an intensifier or to denote disdain.

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.

Virginity is the state of a person who has never engaged in sexual intercourse.

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.

Terms such as "sexual intercourse" or "carnal knowledge" are more commonly found in older statutes, while many modern criminal statutes use the term "sexual penetration" because it is a broad term encompassing (unless otherwise qualified) any form of penetrative sex, including digital (meaning with the digits, i.e., the fingers) or with an object, and may involve only the most minimal penetration.

Oral sex consists of all the sexual activities that involve the use of the mouth and throat to stimulate genitalia or anus.

In general zoology, given the great variety in organs, physiologies, and behaviors involved in copulation, male genitalia are more strictly defined as "all male structures that are inserted in the female or that hold her near her gonopore during sperm transfer"; female genitalia are defined as "those parts of the female reproductive tract that make direct contact with male genitalia or male products (sperm, spermatophores) during or immediately after copulation".

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.

For example, New York defines an adulterer as a person who "engages in sexual intercourse with another person at a time when he has a living spouse, or the other person has a living spouse."

In other cases, condom use is a factor, with some men stating that sexual activity involving the protection of a condom is not "real sex" or "the real thing".

A condom is a sheath-shaped barrier device, used during sexual intercourse to reduce the probability of pregnancy or a sexually transmitted infection (STI).

Amphibians, reptiles, and birds use the same orifice (known as the cloaca) for excreting liquid and solid wastes, for copulation and egg-laying.

Sexual intercourse or other sexual activity can encompass various sexually stimulating factors (physiological stimulation or psychological stimulation), including different sex positions (such as the missionary position, the most common human sex position) or the use of sex toys.

The missionary position or man-on-top position is a sex position in which, generally, a woman lies on her back and a man lies on top of her while they face each other and engage in vaginal intercourse.

While some women find being a receptive partner during anal intercourse painful or uncomfortable, or only engage in the act to please a male sexual partner, other women find the activity pleasurable or prefer it to vaginal intercourse.

Foreplay may precede some sexual activities, often leading to sexual arousal of the partners and resulting in the erection of the penis or natural lubrication of the vagina.

A number of physiological responses occur in the body and mind as preparation for sexual intercourse and continue during it.

Carnal knowledge is an archaic or legal euphemism for sexual intercourse.

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.

In mammals, reptiles, some birds, some fish and certain other groups of animals, this is done by copulation, the penis or other intromittent organ being introduced into the vagina or cloaca.

For instance, screwed up is a euphemism for fucked up; hook-up and laid are euphemisms for sexual intercourse.

Sexual intercourse or other sexual activity can encompass various sexually stimulating factors (physiological stimulation or psychological stimulation), including different sex positions (such as the missionary position, the most common human sex position) or the use of sex toys.

Stimulation can be by self (e.g., masturbation) or by a sexual partner (sexual intercourse or other sexual activity), by use of objects or tools, or by some combination of these methods.

Foreplay may precede some sexual activities, often leading to sexual arousal of the partners and resulting in the erection of the penis or natural lubrication of the vagina.

Vaginal lubrication is always present, but production increases significantly near ovulation and during sexual arousal in anticipation of sexual intercourse.