Īlthough sexually transmitted infections (STIs) 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 transmission) will be exchanged during the activities, especially with regard to aspects that are exclusively non-penetrative. Same-sex couples may also engage in non-penetrative sex to preserve virginity, with gay males using it as an alternative to anal penetration.
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. 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. 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. 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. Non-penetrative sex or outercourse is sexual activity that usually does not include sexual penetration. Drawing by Franz von Bayros showing an act of fingering
