Chastity shorts
From wipipedia.org
Chastity shorts are shorts that cannot be removed by the wearer, hence force him or her to be chaste. They are generally made of leather or rubber. Usually, they are kept on by a lockable belt and also have lockable straps around the ends of the legs.
While they would also work for females, they are normally worn only by males for short-term use.
Such shorts sometimes have a metal or stiff leather plate covering the genitals to make it harder to fondle them through the shorts.
