Fisting is a sexual behaviour that involves inserting a hand or fist into a vagina (vaginal fisting) or anus (anal fisting or handballing). It often leads to orgasm.

Vaginal fisting

Vaginal fisting is performed by both lesbian and heterosexual couples, and some women with very flexible bodies and wrists can do it to themselves.

Fisting is not as impossible as it may seem. In the first place, it is simply an extension of genital manipulation and follows somewhat naturally from the woman's being masturbated by her partner. Perineal massage, an exercise recommended to couples who are preparing to give birth, often results in fisting.

Vaginal fisting became part of public knowledge in a scene (which was not graphically explicit) in Kevin Smith's movie Chasing Amy.

Handballing

Handballing is a kind of anal sex, since a hand is inserted into the anus. Not all anal manipulation by hand results in fisting. Anal fisting is mostly practiced by homosexual men, but not exclusively. Contrary to some myths about gay culture, most gay men don't fist.

Often, the hand is covered with a nitrile (not latex) glove, and is lubricated with a heavy vegetable grease, or vegetable shortening. Sometimes the bottom uses "poppers" (amyl nitrite) as a muscle relaxant when the process is begun. Fisting can be accomplished with no aids, although most beginning bottoms would find it impossible without at least some lubrication.

One of the results of anal fisting can be massage of the prostate gland incidental to the hand insertion.