A strap-on dildo (also strap-on) is a dildo designed to be worn, usually with a harness, during sexual activity.[1] Harnesses and dildos are made in a wide variety of styles, with variations in how the harness fits the wearer, how the dildo attaches to the harness, as well as various features intended to facilitate stimulation of the wearer or a sexual partner.[2][3][4] Strap-on dildos are most frequently used by lesbian women (or women who have sex with women), but can be used by people of any gender or sexuality.[2]
A strap-on dildo can be used for a wide variety of sexual activities, including vaginal sex, anal sex, pegging, oral sex, or masturbation.[5] Sexual lubricant can be used to ease insertion.
Many types of equipment are available, with different features and drawbacks, for a strap-on dildo set up. Often the strap-on dildo will be used with a harness, but some do not need a harness or are built onto one; for these, please see the sections on dildo types and attachment methods.
The first part of a strap-on setup is the harness, which connects the dildo to the wearer's body, usually in a position similar to that of a male's genitals. A good harness should be sturdy yet comfortable, and is often designed to provide stimulation for the wearer.
A two-strap harness, in its most basic form, is similar to a g-string. One strap goes around the wearer's waist, like a belt, while the other goes between the wearer's legs and connects to the other strap in the middle at the lower back. While these are simple, many people find them uncomfortable[citation needed] because the strap rubs against the anus and other areas, and they sometimes do not hold the dildo very firmly, causing it to sag, flop, twist, or squeak.
Three-strap harnesses have one strap around the wearer's waist, but instead of one strap between the legs, they have two straps, one around each thigh, rejoining the first strap near the front. This design leaves the genitals and anus uncovered, and attaches the dildo more firmly, giving the wearer more control. Not all people find this design comfortable, and sometimes they are difficult to fit properly, and tend to slip.