Sounds like T has a chip on her shoulder and is looking for an excuse to insert herself into a situation that doesn’t concern her. How is it her place to accuse you of being transphobic? That’s between you and your boyfriend. From what you’ve said, it sounds like you’re very respectful and understanding of your boyfriend’s gender identity. Even if you did misgender him (which you didn’t), you’re learning and didn’t have bad intentions and it’s rude of your friend to be so snooty about it. Please don’t feel bad, you are not a bigot. People like T are a huge reason why people can be so confused and even ignorant towards the trans community and different pronouns. If someone misgenders a person on accident and they immediately have someone barking in their ear about how much of a bigot they are, that’s gonna make that person extremely self conscious and not even want to learn from or understand their mistake. If anything, T owes you an apology for speaking for your boyfriend and accusing you of something you didn’t do.