Oral sex consists of all the sexual activities that involve the use of the mouth, tongue, etc., to stimulate the genitalia. It may be used as foreplay before intercourse, or as climax of a sexual act.
A common technique of fellatio is to take the glans (head) of the erect penis in the mouth while rhythmically caressing the rest of the penis with the hands; the testes and the shaft of the penis can also be licked with the tongue. Suction is often used to increase the pressure and friction exerted on the penis. (When the testes are taken into the mouth, the act is sometimes known as "teabagging" due to its supposed similarity to the action of dipping a teabag). Depending on the preference of the participants, this stimulation may produce an orgasm and ejaculation of semen which may or may not be swallowed, hence the phrase "spit or swallow".
While the use of the mouth to stimulate the penis, especially the glans, is a central feature of fellatio, often the partner simultaneously stimulates the shaft of the penis with her/his hand to provide the man with the feeling of the penis being enclosed.
The practice of passing semen from the mouth of the fellator to that of the fellatee, or to the mouth of another participant, is known as snowballing. However, if the partner is unwilling to swallow or allow the semen into their mouths (and spit it back out), a common variant consists of the fellatee ejaculating over the fellator's face/body. The slang term for this is a facial. Some couples prefer the facial as an act of sex play and not of an unwillingness to swallow. If the ejaculate is squirted on the neck/chest of the fellator, it is known as a "pearl necklace".
A technique requiring skill and practice is known as deep throating, named after a 1972 pornographic movie which features it. This technique involves taking the entire erect penis in the mouth, the shaft bending slightly to allow the head of the penis to slide partially down the throat of the fellator.
The practice of using the teeth covered by the lips during fellatio is known as t-boning. Though some males find the sensation of teeth on the penis to be arousing, if done incorrectly it can be painful or too intense.
A small percentage of men have the penis length and/or body flexibility to fellate themselves, or to autofellate.
The common term blowjob is misleading, as blowing is not normally part of fellatio. In fact, blowing air into a partner's penis is an unhealthy practice. The opposite, sucking, is much more appropriate.
Cunnilingus is the act of using the mouth and tongue to stimulate the female genitals, especially the clitoris. The term comes from an alternative Latin word for the vulva (cunnus) and from the Latin word for licking (lingere). Some 33% of women report never or seldom achieving orgasm during intercourse, and cunnilingus is a way for many women to achieve orgasm with a partner.
As in all human sexual behavior, the variety of techniques in cunnilingus and individual responses to them are almost endless. As always, communication, experimentation and practice are the best way to learn how to please a particular partner.
The clitoris is the most sensitive part for almost all women, but may be too sensitive to stimulate directly at times, especially in earlier stages of arousal, and it's often best to begin with more gentle and less focused stimulation of the labia and the whole genital area.
Tongue tip, blade or underside can be used, as can the nose, lips and teeth (with caution). One can suck, sip, lap, nibble, etc. Movements can be slow or fast, regular or erratic, firm or soft, as the moment requires.
The tongue can be inserted into the vagina, either stiffened or moving, and someone with a long or very flexible tongue may be jokingly considered very desirable. This can be combined with stimulation of the clitoris by the nose, if one's facial proportions are appropriate.
Humming while performing cunnilingus is often considered to be especially arousing, with certain pitches, rhythms or tunes thought to be particularly effective by different people.
Cunnilingus is easily accompanied by the insertion of finger[s] or a sex toy (for example, a vibrator or dildo) into the vagina, which allows for the simultaneous stimulation of the G-spot, which many women find produces very intense sensations. Many other activities can accompany cunnilingus to enhance overall pleasure, of course, limited only by preference, physics, anatomy and multitasking ability.
Irrumatio is similar to fellatio, but involves the penis actively penetrating the mouth as a passive orifice, making the involvement of the person thus penetrated a passive one, with little control over the proceedings. A slang term for this is "face fucking".
Facesitting is a form of oral sex in which the receiver sits on the giver's face and pushing into it with his or her genitals.
Oral sex can be performed by both partners at the same time in a sixty-nine position.
The receiver of oral sex may find it pleasurable if the giver hums or sings at the same time, sometimes called a hummer. This in effect makes the giver's mouth into a vibrator, though unlike mechanical vibrators the mouth has built-in lubricant (saliva). A similar effect can be created by placing a small, yet powerful vibrator under the jaw, causing the tongue to vibrate, which can be very pleasurable in small quantities, but can be numbing for one or both parties if overused.
Also, eye contact during fellatio or cunnilingus may be very stimulating and more pleasurable.