I (39M) teach part-time boxing classes on Friday and Saturday evenings, and usually have quite small groups of students, including male and female, between the ages of 18 and 35. The class welcomes students of all levels, so we sometimes have people who have never taken boxing, and people who have been doing it for years.

Last week, I had a girl in her 20s show up. She seemed like it was her first time, although she had some experience with other types of martial arts. She did not carry herself confidently, was looking down, and had to get some additional instruction. She had a very shy demeanor, and would not look at anyone in the eyes. Towards the end of the class though, she was getting into it and was actually making some progress, which I was happy to see.

Now, to the issue: we had a class of about 6 individuals, including her. She had short hair, and a large t-shirt on, whereas the other girls were dressed in very feminine gym gear. I didn't pay attention, and made the mistake of using "he" pronouns for her at first, then making a stupid comment about how there are exactly 3 guys and 3 girls in the class. She looked very uncomfortable, and looking at her, I realized I made a stupid mistake. In order to fix this, I went up to her and asked for her pronouns. She said it's she/her. It was very uncomfortable for both of us, and she looked like she was on the verge of tears.

Later, I found out she had complained to my boss. The girl had pulled her aside after the class and basically had broken down in tears. As far as I understand, she is a cis woman, who had serious body dysmorphia issues (and according to my boss had even gotten cosmetic procedures to appear more feminine). Her coming to my class was a big step for her, as she never did group sports due to her condition. I felt terrible, but cannot apologize to her as I don't have her contact information and she has not shown up to the class since. My manager told me straight up that from now on I should ask for everyone's pronouns when I begin the class, rather than having anyone singled out, as it might be very uncomfortable. So AITAH for asking for a cis womans pronouns?