Ball binding
From wipipedia.org
Ball binding is the act of tying up the scrotum of a male (and often penis too), usually with rope ("balls" being a slang term for testicles). It is often an addition to bondage, and is sometimes done for humiliation. If the ropes are tight and painful, it can be regarded as genitorture; care must be taken not to cut off the blood supply for a long period, or the genitals can be permanently damaged (see Advice: Genitorture).
If the ball binding is not attached to other ropes, it does not in itself contribute to the bondage. However, it may be attached to a crotch rope joined also to wrist bonds as a way to restrain the arms.
