I was shitting at school today and I got violated

I was taking a dump in the stall early in the morning. The guy in the stall next to mine got out of his and knocked on mine.

He asked me if I was jerking off. I told him wtf why would you even say that, he stayed quiet. He goes back into his stall and I begin hearing rubbing noises. He is 100% masturbating in the stall next to me. He was doing it loud and on purpose so I could tell. I was stunned and shocked and didn’t know what to do. He then tries to show me something he typed out on his phone from under the stall.

I didnt even look at the screen before asking him again wtf are you doing. He retracted his hand and the rubbing noises continued for a bit longer until he left. I was too shocked and uncomfortable to confront him. I don’t know who it was. I dont have a clue who would do that. I just had the misfortune of being in the bathroom at the same time as this sicko.

I feel so violated and disrespected. I didn’t want to fight him because I already got into trouble this year with someone else. I just sat there and listened to him jerk off right next to me and I didn’t even say anything I just let him. I’ve felt so sick all day, I’ve only told my parents. I don’t know what to do or who to talk to.