Verrouille It depends on ones definition of BDSM, but in most cases, I suspect it meets the definition. I don’t personally think of my marriage as BDSM, but I wear a belt, obey my wife, and accept corporal punishment in disagreements. To me, that’s simply the way we have adopted — it’s a 1950s nuclear marriage with added steel equipment. In bed, we’re actually pretty vanilla. But most would probably call it a BDSM relationship.
All other things aside, a belted relationship means that one partner accepts the absolute authority of the other in at least one area, and submits to being forcibly locked to maintain it. That at least counts as power exchange.