I'm a teacher. Whenever kids ask me to affirm their made up identity( only 2xs), I tell them that they will be addressed as presented on the legal paper work, so maybe they should have their parents change the paperwork with an attorney and stuff. Then i ask if they would like me to address it with their parents for them. That's usually the end of it. I tell them imagination and pretend are for elementary school, and in my class we only deal in facts.