Sex position A sex position is a position of the body that people use for sexual intercourse or other sexual activities. Sexual acts are generally described by the positions the participants adopt in order to perform those acts. Though sexual intercourse generally involves penetration of the body of one person by another, sex positions commonly involve penetrative or non-penetrative sexual activities. Three categories of sexual intercourse are commonly practiced: vaginal intercourse (involving vaginal penetration), anal penetration, and oral sex (especially mouth-on-genital stimulation). Sex acts may also involve other forms of genital stimulation, such as solo or mutual masturbation, which may involve rubbing or penetration by the use of fingers or hands or by a device (sex toy), such as a dildo or vibrator. The act may also involve anilingus. There are numerous sex positions that participants may adopt in any of these types of sexual intercourse or acts; some authors have argued that the number of sex positions is essentially limitless. History Sex manuals usually present a guide to sex positions. Sex manuals have a long history. In the Graeco-Roman era, a sex manual was written by Philaenis of Samos, possibly a hetaira (courtesan) of the Hellenistic period (3rd–1st century BC). The Kama Sutra of Vatsyayana, believed to have been written in the 1st to 6th centuries, has a notorious reputation as a sex manual. Different sex positions result in differences in the depth of sexual penetration and the angle of penetration. Many attempts have been made to categorize sex positions. Alfred Kinsey categorized six primary positions, The earliest known European medieval text dedicated to sexual positions is the Speculum al foderi, sometimes known as "The Mirror of Coitus" (or literally "a mirror for fuckers"), a 15th-century Catalan text discovered in the 1970s. Exclusively penetrative These positions involve the insertion of a phallic object(s) (such as a penis, strap-on dildo, plug, or other nonporous object(s)) into a vagina, anus or mouth. Penetrating partner on top with front entry The most used sex position is the missionary position. In this position, the participants face each other. The receiving partner lies on their back with legs apart, while the penetrating partner lies on top. This position and the following variations may be used for vaginal or anal intercourse. The penetrating partner stands in front of the receiving partner, whose legs dangle over the edge of a bed or some other platform like a table. With the receiving partner's legs lifted towards the ceiling and resting against the penetrating partner, this is sometimes called the butterfly position. This can also be done as a kneeling position. The receiving partner lies on their back. The penetrating partner stands and lifts the receiving partner's pelvis for penetration. A variant is for the receiving partner to rest their legs on the penetrating partner's shoulders. The receiving partner lies on their back, legs pulled up straight and knees near to the head. The penetrating partner holds the receiving partner's legs and penetrates from above. Similarly to the previous position, but the receiving partner's legs need not be straight and the penetrating partner wraps their arms around the receiving partner to push the legs as close as possible to the chest. Called the stopperage in Burton's translation of The Perfumed Garden. The coital alignment technique, a position where a woman is vaginally penetrated by a man, and the penetrating partner moves upward along the woman's body until the penis is pointing down, the dorsal side of the penis now rubbing against the clitoris. The receiving partner crosses their feet behind their head (or at least puts their feet