Foreplay

In human sexual behavior, foreplay is a set of intimate psychological and physical acts between two or more people meant to increase sexual arousal.

Foreplay involves different acts such as kissing, touching, embracing, talking, and teasing (teasing, in this case, may include methods of satisfaction, such as erotic sexual denial). Sexual stimulation of all kinds, such as manual or oral stimulation of erogenous zones are considered foreplay. Sexual role playing, fetish activities, and BDSM can also be considered foreplay, though they may also accompany intercourse and not just precede it. Of the various forms of foreplay, the most common include fellatio and cunnilingus.

If no intimate sexual acts are intended, foreplay-type actions are often classified as flirting, "fooling around" or, in colloquial terms, being "touchy-feely". Since these interactions are non-explicit, there can be misunderstandings about whether an invitation has been extended or accepted. Inadvertent or not, this kind of miscommunication is often termed "leading someone on."A romantic, intimate, or overly sexual atmosphere can be considered a gesture of foreplay. Foreplay can begin with non-physical behavior that signals sexual availability. Verbally, foreplay may include compliments, subtle comments with double entendre, and intimate conversations. Non-verbally, foreplay can include provocative clothing, preening gestures, winking, licking or biting one's lips, standing inside a partner's personal space, and holding a gaze longer than is acceptable for casual acquaintances.

Progression
Foreplay eventually turns physical. Simple and possibly innocuous acts, such as straightening someone's clothing or hair, bumping into someone while walking, stroking someone's arm, or whispering in someone's ear can constitute foreplay. One may also hold hands, touch the face, kiss, "bite", tickle, or massage. As comfort increases, so usually does the level of intimacy. More intimate examples include: Deep tongue kissing, also known as French kissing; Touching and massaging erogenous zones over clothing, also known colloquially as groping or "heavy petting";
Rubbing together erogenous zones over clothing, also known as dry humping or grinding; Undressing oneself or partner, also known as stripping.

There are many types of foreplay. Stimulation with the hands is the most common form, followed by oral stimulation. Foreplay is to provide sexual pleasure and arousal. The act is generally the act of preparing ones partner for sexual intercourse, though it does not exclude the chance of orgasm if applied rigorously.

Direct manipulation of naked erogenous zones is almost always considered foreplay (except, of course, in a medical context). In women, this includes stimulation of the clitoris and vulva. In men, it includes stimulation of the penis and scrotum. For both sexes, it could include stimulation of nipples and anus. Stimulation can be achieved by mouth, hands, sex toys like dildos or vibrators, or common household objects like feathers or ice cubes. Direct manipulation of naked erogenous zones is not considered foreplay when it is not preparatory for further sexual acts. For example, mutual masturbation and oral sex are often considered final sexual acts; as final acts with no expectation of further sexual congress, these are not considered foreplay.
Foreplay tends to become purely physical and intense. It reaches its peak in the moments just before intercourse, when it induces a strong mutual desire for penetration. Some genital teasing may take place for a brief time. Technically, foreplay ends with intromission, or the beginning of intercourse. In practical terms, however, the continuity between foreplay and intercourse may be very great, since the couple may engage in foreplay-like behavior during intercourse.
Safe sex practices can be incorporated as part of foreplay. A condom or dental dam can be applied in an erotic or playful way as part of the final stages of foreplay.

Function and effects
Psychologically, foreplay lowers inhibitions and increases the emotional comfort of the partners. Physically, it stimulates the process that produces an erection in men, allowing them to penetrate an orifice. In women, it helps stimulate the process that leads to erection of the clitoris, raising of the cervix (elongation of the vaginal canal), and the production of vaginal lubrication, allowing penetration to take place comfortably.
For likelihood of orgasm foreplay is of little or of no help, only intercourse matters most, finds a survey administered to 2,300 Czech women.

Research
Foreplay can vary dramatically based on age, religion, and cultural norms. In spite of the clichéd modern folklore that women demand more foreplay and require more time to become aroused, recent scientific research refutes that myth. Scientists from McGill University Health Centre in Montreal, Canada used the method of thermal imaging to record baseline temperature change in the genital area as the definition of the time necessary for sexual arousal. Researchers studied the time required for an individual to reach the peak of sexual arousal and concluded that, on average, women and men spend almost the same time for sexual arousal around 10 minutes.