Sexual frustration
From wipipedia.org
Sexual frustration describes the condition in which a person is in a state of agitation, tension or anxiety due to a quantity of sexual activity and/or sexual satisfaction that is less than the person's sex drive, or where they are sexually aroused but unable to act on the feeling.
A dominant will often use erotic sexual denial to create a state of sexual frustration in his or her sub as an element in a scene.