When I was 13 years old I did something very wrong. Back in the day in my middle school was fucked up trend: slaping girl’s asses. I didn’t have the courage to do it myself so when we had family reunion I decided to practice with my 5 years old cousin. When I was playing with her I slightly spanked her butt over the clothes multiple times. Then I continued with slightly pulling her pants down and then I slightly spanked. Once I had pulled so much that I saw her private parts and in that moment I had realized that I messed up. Since then I have never repeated such disgusting behaviour, yet my guilt and selfhate for this action has been slowly increasing.
Nowdays with my cousin I have good relationship, I sometimes help her out with school work. She doesn’t seem to be uncomfortable around me.
Am I a disgusting person?
You did something due to peer pressure at an age when kids are obsessed with fitting in. In the course of doing so, you realized it was wrong and you stopped. Even now, presumably years later, you still feel bad about it. I’d say you’re good, every single one of us has done things (often involving inappropriate actions) we look back on and regret. You’re fine.