A crotch rope (also known an a Crupper in Europe and Sakuranbo in Japanese bondage) is a form of bondage rope harness, where a basic tie encircles the waist, and a second, perpendicular rope goes through the legs from front to back.
Depending upon how tight the ropes are tied, the size of the rope, and the length of time they are worn:
- it could be used to hold a vibrator or butt-plug in place,
- it could be erotic (if the rope is medium size and made of cotton or nylon)
- it could be a punishment (if the rope were very thin or made of a rough cordage)
Crotch ropes appear regularly in the drawings of Robert Bishop.