What’s the meanest thing you’ve ever said to someone?

In my freshman year of high school, a girl kept calling me ugly. So one day I started announcing to the class that something smelled bad and started looking around for it. I kept that up for a couple of weeks. Then one day I loudly announced to everybody that it was that girl and that I had to switch seats because her stench was repulsing me.

All of these years later I have realized that she had a crush on me and was handling it stupidly. I feel bad about that now.