Wait a bit... does Sadism require volunteering on the part of the "recipient"? I do not trust Wikipedia as the final authority on things, but here is a relevant bit:
================== "Sadism" and "masochism," in the context of consensual sexual activities, are not strictly accurate terms, at least by the psychological definitions. "Sadism" in absolute terms refers to someone whose pleasure in causing pain does not depend on the consent of the "victim." Indeed, a lack of consent may be a requisite part of the experience for a true sadist. ==================
Your sarcasm may be premature!
--ravi
P.S: the Wikipedia article offers the distinction between Sadism and the S of BDSM.