NTA. At all. I want to put it in other terms: you happen to be non-binary and someone you just meet misgenders you and then jokes about it. It’s not funny. A quick and forward correction like: “My pronouns are (insert pronouns here), I appreciate your trying harder to honor that.” Your speech, gender-identity, appearance, and all of your personal traits are not other people’s playgrounds. I have been told before when firmly yet appropriately correcting someone who insults me that “I need to have a thicker skin if I’m going to dish it out, I’d better be able to take it.” My response was simple: “I’m happy to be funny and find humor in things that we mutually agree on as funny. Something that I can’t help (my speech, in this case - for you and me) is not one of the things I agree to letting be part of our banter.” What your psyche is saying when you come across as super-cutting, as some might experience your remark , is “I have clear boundaries of comfortability with myself and I’ve struggled enough with my speech that I don’t need you pointing it out to me or anyone else - it’s my story to tell, should I choose to tell it.” You may want to consider being slightly less aggressive with your retort to a comment like that and use people’s conscience against them in a slight manipulative yet IMO appropriate way: “I don’t need you to point out my stutter, I’m well acquainted with it and and don’t need it pointed out to me, of all people. I would appreciate the same tolerance, respect, or even curiosity about it - the that you would have every right to expect if you were in my shoes.”