I'm just gonna pretend you have one anyways since I don't regret misgendering someone. I I were a mcdonalds or chick fil a cashier and someone told me they were they/them, I'd charge them double the price, and when they tell me they said they were they/them, I would respond with "doesn't they mean more than 1 person? You probably have another person with you. What is it? Your nonexistent mother. Well, your father doesn't exist as well, but he's abusive, so makes sense you didn't bring him."