frotting

Frot or frotting (slang for frottage; from French frotter 'to rub') is a gay sexual practice that usually involves direct penis-to-penis contact. The term was popularized by gay male activists who disparaged the practice of anal sex, but has since evolved to encompass a variety of preferences for the act, which may or may not imply particular attitudes towards other sexual activities. This can also be used as some type of foreplay.
Owing to its non-penetrative character, frot has the safe sex advantage of minimizing the transmission risk for HIV/AIDS; however, it still carries the risk of skin-to-skin sexually transmitted infections, such as HPV and pubic lice (crabs), both of which can be transmitted even when lesions are not visible.
It is analogous to tribadism, which is vulva-to-vulva contact between women.

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