Before we can discuss the sacred nature of S/M it is necessary to define S/M, usually pronounced S (ess) and M (em). Sex, and particularly "nontraditional sex", has been demonized and clouded with mystery, misinformation, and misunderstandings.
Whenever there is something that is *not nice to talk about* the silence will be filled with lies. Sexuality and all its diverse sacred meditations is no exception to this rule.
What is S/M? Sado-masochism is the term for sexual expression that focuses on the body's reaction to pain or other stimulation which is not usually considered pleasurable. By the strictest definition, a sadist is one that derives pleasure from another's pain. A masochist is one who finds pleasure in her or his own pain.