People in adult relationships should not "HAVE TO" do anything. It should always be mutual consent. The term in the fetish community (and we are talking fetish here, are we not?) is "Consenting Adults". To be placed into a "have to" position is not how adults are supposed to do relationships. Requirements are for college courses, not relationships.
And what do we mean by "participate" anyway? Are we talking about little things, like sharing lipstick, shopping, or picking out clothes, or - as I suspect - are we talking about very exact and specific sexual acts and psycho-sexual drama? Huge difference. To get the real answer you require, you must begin by asking the question you really want the answer to.