In some cultures, sexual activity is considered acceptable only within marriage, while premarital and extramarital sex are taboo.
For example, the relationships can be ones of marriage, intimate partners, casual sex partners or anonymous.Sexual activity can be regarded as conventional or as alternative, involving, for example, fetishism, paraphilia, or BDSM activities.Fetishism can take many forms ranging from the desire for certain body parts, for example large breasts, armpits or foot worship.It can be divided into acts which involve one person, also called autoeroticism, such as masturbation, or two or more people such as vaginal sex, anal sex, oral sex or mutual masturbation.If there are more than two participants in the sex act, it may be referred to as group sex.
Autoerotic sexual activity can involve use of dildos, vibrators, anal beads, and other sex toys, though these devices can also be used with a partner.
Sexual activity can be classified into the gender and sexual orientation of the participants, as well as by the relationship of the participants.
Human sexual activity, human sexual practice or human sexual behavior is the manner in which humans experience and express their sexuality.
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.
Sexual activity normally results in sexual arousal and physiological changes in the aroused person, some of which are pronounced while others are more subtle.
Sexual activity may also include conduct and activities which are intended to arouse the sexual interest of another or enhance the sex life of another, such as strategies to find or attract partners (courtship and display behavior), or personal interactions between individuals (for instance, foreplay or BDSM). Human sexual activity has sociological, cognitive, emotional, behavioral and biological aspects; these include personal bonding, sharing emotions and the physiology of the reproductive system, sex drive, sexual intercourse and sexual behavior in all its forms.