Mainly the judo section, this is the key event that traumatized me because she was being groped (by boobs and ass, taking advantage of the moment in the ground grappling) by a few boys my age (11-12) and I heard them discussing her
After that I had erotic nightmares in which these two boys do whatever they want to her, and at some point she breaks down and enjoys herself
And later I became fascinated with this topic, began to fantasize about what my friends, enemies and so on do with it, a little later, when I began to have a regular sex life with girls, it remained only within the framework of fetish, sometimes I even like to play a bully in role-playing games with a girl.
I think in my case specifically there were just stupid events that broke me, I didn't originally have any cuckold fetishes, now I kinda don't care, I don't think or fantasize about her, I just like this type of content