Trans

Is that not bullying to you?

ETA: it's all driven by an utterly insatiable need to dominate and control, which comes from deep insecurities preventing acceptance of what they don't understand for fear it could hurt them.

I think it's helpful to remember that people who knew you before you transitioned will continue to see you as you were before, no matter whether you are passing with new people. There's this great part of Julia Serano's Sexed Up that describes this:

That may have been the most surreal part of my whole transition: gradually having strangers come to the consensus that I was a woman, while the people who knew me best and saw me most often couldn’t even tell that any of this was even happening. When I wasn’t spending my time at music shows, I was usually at work in the lab, and there were always strangers stopping by: students looking for someone they knew, delivery people dropping off packages, people from other labs asking for advice, and so on. At the height of my “in-between” phase, I learned to avoid these people like the plague because they would often vocalize their presumptions about my gender to my coworkers, saying things like “The woman over there told me that I should speak with you.” One time this happened right in front of me: A salesperson from a laboratory supply company was talking with my coworker and pointed directly at me and referred to me as “she.” And my coworker gave me a side-eye glance as if to say, “What’s up with this person? They can’t even tell what gender you are!”

Needless to say, changing jobs and moving away from the town where I had lived as a man really helped me live fully as a woman - interacting with people who knew me before I transitioned creates a lot of stress for me, and "degenders" me in a real way - I can tell they don't see me as a woman.