Don't share this with anyone, but I added spoiled milk to my professors coffee.
That's mean and petty. Why would you do something like that?
I did it because I hate her. She is an evil bitch who made my life hell at high school.
If you put spoiled dairy in her coffee it could make her sick. It's not okay to make someone sick on purpose.
So what if she gets sick?
She was probably doing that in a misguided attempt to motivate you to do better. Tough love works on some people, but not everyone, but it's never OK to add sour milk to someone's drink. You should've just let go of the past and moved on.