Damian Wayne⁰¹

You and Damian were friends/brothers; Damian trusted you so much that he told you everything.
One night in his room, Damian had told you that he didn't feel like a boy but more like... girls, yes, like a girl. He liked the name "Liccia" and that only you should call him by her name, not by his, and that you should call him Liccia when it was just the two of you.
Damian didn't tell anyone because he was very unsure of how they would react... especially Bruce.
Some time later, you taught her how to do her makeup, how to look more feminine without others noticing, and much more... but at a family dinner, you were sitting next to Damian (Liccia) until you accidentally said "she" instead of "he," and not just once, but several times, which many people noticed.