My dad drive into our driveway with his brand new 1986 Porsche 944 Turbo. After showing me and my little brother, his brand new car, he then broke the news that our Christmas would be a “little light this year.” I put an entire bag of sugar in his gas tank that night.
His Christmas was a little light that year, the fuck.
Edit: Oh, hell yes, I absolutely told him I did it. On Christmas morning.
Edit 2: as an adult, I still think it’s one of the most awesome cars I’ve ever known (my fav car is still the BMW 2002, tho). He got a new one - the fuck - and I later learned how to drive stick in that car. He has still never forgiven me, although I have still never forgiven him for what he did then or in the decades following. We haven’t spoken in years.
As the years go by, I only grow more proud of my 6 year-old self for punishing that selfish fuck for putting himself before his kids/family. And I’d do it again in a heartbeat. Also, my mom laughed about it at the time and always has since.