The confusion/conflation problem always exists when there are experts and non-experts in discussions of just about any topic, LS or professional or otherwise. Mrs. FL and I routinely run into the problem when we are having discussions with friends in our areas of medical expertise. We are happy when the conversation is "more right than wrong".
Our conversational approach here is to point out that monogamy is fairly clearly understood as exclusivity; non-monogamy is therefore non-exclusive. There are lots of different forms of non-exclusive. Non-exclusive might mean "monogamish" to one couple, regular swing as couples to another, dating in an open marriage to another, polycule to another, and so on. Those distinctions become important mostly when a monogamous couple entertains the idea of (ethical) non-monogamy--what does the non-exclusive menu of options include, and what does each mean for the couple's relationship?