Redditors, what was the most petty revenge you’ve gotten on someone, what did they do? Do you regret it?

Gave my dad his least favorite Gatorade two days before he went to the hospital and died. I also yelled at him for yelling at me about the flavor. You abused me for years. I can’t kill you, but I can give you nasty drinks.

No regrets, except maybe that I didn’t poison it.