Sure, my late partner at Lenny and I were consensually non-monogamous. But that didn't mean we just did whatever we felt like. We talked about what our intimacy boundaries were regarding other people, we agreed on a certain set of behavior rules, and we agreed to complete transparency.
I won't bore you with all the details, but I knew what the rules were, and if I had broken them, I would have been cheating.
Binary is a popular word this year, so let's say that our relationship didn't fall on either side of a monogamous/non-monogamous binary.
I don't know too many relationships in the gay world that do, not personally.