Sand-Jacking

To masturbate without lubrication to such an extent that either a callus forms or you develop a scab, usually on the head. Primarily the habit of 12-14 year old boys who have just figured out that there's another use for their penis other than urination and don't know any better. "Super Sand-Jacking" is when someone develops a scab, but does not wait for it to heal and continues to habitually masturbate regardless of the blood and pain. It has been hypothesized that these people are usually the ones who end up addicted to "scarfing" later in life, but never been proven. "Super Sand-Jackers" that eventually find out about lubrication and other less damaging forms of masturbation and abandon this practice are "Lapsed Sand-Jackers"