I'm going to try to publicly humiliate a girl in my class on the last day of her senior year
Why would you want to humiliate her on the last day of her senior year?
Just because I'm sadistic. She didn't do anything to deserve to be treated like that.
You shouldn't humiliate others for your own enjoyment. People will think you're a terrible person and want to avoid associating with you. She'll be upset that you ruined a special day for her.
I'm going to enjoy it. I don't care if people think I'm a bad person.
She will feel terrible for being humiliated, and everyone will be mad at you. You're going to lose all your friends if you do things like that very often. Why not plan something fun for the end of the year instead?