We probably need to define "sex' too. Is it just penetration and oral or would you include manual stimulation (IE things like a magic wand etc)?

That raises the whole issue of release vs no release in the context of pro BDSM play.....something that has been hotly debated on various forums before. I fall solidly in the "yes, release" camp but to to each their own.

If made to choose between a vanilla sexual relationship and a BDSM one that included plenty of orgasms but no "sex" as such I would be far more torn.