Well that is an unnecessary hypothetical, simply because I don't thiink it's a realistic every day (or even every lifetime) scenario. The likelihood of any merkin actually coming face to face with a person who prefers to be referred to an a unisex, intersex or omnisex gender is a squillion to one. AND if it did happen, why not just move on ?
I have once had a client who approached life from an alternative perspective, so much so that he referred to himself as Snow. I believe that he was an artist if some sort. Indeed his wife actually referred to him as Snow when we spoke on the phone. I am unsure of his gender, however in the absence of this critical information, I left that part of the form in my mind blank. No biggie and really, who gives a crap. He and his cohort are not impeding my lifestyle, f**king with my hunting and gathering or c**k blocking my primal urges. Carry on I say.
I like society being a version if the Star Wars Cantina, with different races, religions and even genders if that's what floats your boat. FMD who wants to live in the land of vanilla merkins like a paddock of 10,000 sheep.