Where does it fit?

I was talking to a friend yesterday about her definition of the difference between a bdsm practictoner, a  fetishest  and a hedonist. She placed people involved in M/s and D/s dynamics in the bdsm practitioner category whereas I did not. I see M/s & D/s as relationship dynamics which in and of themselves aren't different than any other way someone might decide to handle their relationship but with kinky accoutrements. I think it gets thrown in with the bdsm crown b/c quite often the people who practice those relationship dynamics also enjoy bdsm activities within those relationships. There is also the common habit of collaring and oft seen deference  slaves show for their masters which evokes strong reactions in people who witness it given our current societies leaning toward egalitarian relationships.   Having a place where one can behave publicly as one wishes without concern for the sensibilities of people not privy to the inner working of your relationship draws many to the public scene even if the don't practice bdsm since people who are involved in flogging and other interesting activities are less likely to raise an eyebrow over a significant other who is catering to your every whim. At least that seems to be the thought process.