If you don’t know someone’s gender, what do you call them? Like, what if they present in a really ambiguous way? Or what if you’ve never even met them? Like say you’re about to sit down at a restaurant, and you notice a jacket on the seat, would you tell the hostess, “excuse me, I think the last person to sit here left their jacket.” Or would you just be unable to refer to them because you don’t know their gender?