Dry hump

Non-penetrative sex or outercourse is sexual activity that usually does not include sexual penetration. 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. Some forms of non-penetrative sex, particularly when termed outercourse, include penetrative aspects, such as penetration that may result from forms of fingering or oral sex.

People engage in non-penetrative sex for a variety of reasons, including as a form of foreplay or as a primary or preferred sexual act.Heterosexual couples may engage in non-penetrative sex as an alternative to penile-vaginal penetration, to preserve virginity, or as a type of birth control.Same-sex couples may also engage in non-penetrative sex to preserve virginity, with gay males using it as an alternative to anal penetration.

Although sexually transmitted infections (STIs/STDs) such as herpes, HPV, and pubic lice can be transmitted through non-penetrative genital-genital or genital-body sexual activity, non-penetrative sex may be used as a form of safer sex because it is less likely that body fluids (the main source of STI/STD transmission) will be exchanged during the activities, especially with regard to aspects that are exclusively non-penetrative.

While non-penetrative sex (or outercourse) is usually defined as excluding sexual penetration, some non-penetrative sex acts can have penetrative components and may therefore be categorized as non-penetrative sex. Oral sex, for example, which can include oral caress of the genitalia, as well as penile penetration of the mouth or oral penetration of the vagina, may be categorized as non-penetrative sex. Oral sex may also be considered outercourse solely because it is not vaginal or anal intercourse.

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Wikipedia