As simple as it sounds. Sometimes our kinks are mysterious, but sometimes you can look back and see a clear origin for them, whether that be a traumatic response or a childhood hobby or something.
For me? While figuring out my bisexuality, i also played a lot of fighting games.
Seeing two female characters throw each other in Soul Calibur or Dead or Alive was one of the earliest examples of female physical contact that i got that my parents didn’t immediately try to ban so like… it stuck with me and now as an adult i get turned on by certain kinds of fights or martial arts gear.
One that I remember, it at least when I first realized it turned me on anyway, was when a woman and her girlfriend attempted to sexual assault me. I was able to get away but I was also crazy aroused.
I have a huge kink for CNC with a woman as the aggressor now.