What's the worst thing you've ever done

I also dropped a lit cigarette accidentally on a giant lunar moth once and burned a hole in its wing. I hadn't seen it on the ground. I freaked out and tried to step on it but it was so big it didn't die, and I couldn't stand to do any more. My friends saw it later and were like "god what kind of sicko would do that?" and yeah I feel much worse about that than cheating.

Seven or eight years ago my brother stomped a cat do death. We drove on the road and it lay there twitching, totally disfigured from being hit by a car. I could hear the cranium crack when he stomped on it, some really horrible stuff that I have a crystal clear memory of to this day.
 
i said mean things to a girl and made her cry. also, i went to another country telling her i would come back but i never did.
 
I cut off my long hair once...its was the worst thing I ever did.
 
Seven or eight years ago my brother stomped a cat do death. We drove on the road and it lay there twitching, totally disfigured from being hit by a car. I could hear the cranium crack when he stomped on it, some really horrible stuff that I have a crystal clear memory of to this day.

This reminds me of House of Leaves when the bimbo tosses the puppy out of the window. Kinda disturbing when I read it, so I could see how the memory stuck with you.
 
One time I pissed my sleeping bag at my grandparent's around the age of 9, and then dragged my youngest brother (~4) into it so he would get the blame. My parents still laugh about it happening every once in a while, unaware that I did it.

EDIT: Reading through this thread, I didn't think about not responding to calls. I don't do it because I'm an asshole though (or so I think). Rather, I'm a total social failure that often can't even respond to friendly PMs on metal forums, as I worry that I may say something that appears assholeish, rewrite it several times, and then just pretend to have never noticed it in the first place. In the real world that translates into emails and phone messages being "ignored"... in fact, most people have to say something to me several times to get my attention as I worry that they aren't talking to me and that I would look ridiculous if I responded to them. Thus, I adapt the exterior of a smug self-absorbed asshole to hide my extreme anxiety and insecurity.

Since that's all rather off topic I guess I'll bring up the time I threw those spiny seed-ball things from trees at kids running by for track-and-field in 6th grade.

I once convinced a forum that I was a ten year old paraplegic with cancer and dead parents as well, although being mean to gullible fools on the internet is hardly a terrible crime.

Also threw a handball straight at the back of a kid's head while he was doing pushups once, which scraped his face up a bit. Also threatened to electrocute my brother to death with a lightbulb, which caused him to cry and run away. It was technically for self-defence (he had just pulled a kitchen knife out on me) but he only did that because I tipped over his Lego castle.
 
In 7th grade, i remember i had french class, and i used to piss off the teacher in every class. So one day, i threw an eraser onto her ass when she was writing on the blackboard, and she turn around and was pissed off, and at the same time some guy was stretching his arms up in the air, and the teacher thought he was the one who threw it, he immediately got sent off to the principle's office, and i think he got suspended from school for 2 weeks.

I remember i once threw my friend's backpack out of the window.

I've done many crazy things when i was in school.
 
Beat a possum to death with a metal bar...
The first time I hit it, I broke its back, and it stared at me making this god awful sound before I smashed it across the head and sent it flying.

Broke up with a girlfriend of four months over facebook then didnt talk to her for over a month because I didnt want to hear her cry...

There's plenty more, but those two things stick out in my mind as particularly mean spirited. :(
 
This kid was chirping me in gym class in grade 1 or 2, while we were throwing around softballs in the field... I remember his name was Ian. And he was just being a really fucking chirpy bird.

I lost it and just fucking LAUNCHED a softball right between his eyes. He had to go to the hospital. Nobody saw so I never got in any shit.

It was pretty funny because I think he moved after that. That was the only time I've ever lost my temper to that degree though.
 
Man, you people have done some pretty terrible shit.

Probably the worst thing I've done is accidentally break my little brother's finger in a door hinge once while playing around. He was chasing me down the hallway of the house and I ran into my bedroom and slammed the door behind me, not realising how close he was or where he had stuck his hand. I was probably 9 or 10 while he was 4 or 5.
 
I was about 14, me and my mom were arguing about me not being allowed to go anywhere because I was caught smoking and at that time, my dad was dead for about 7 years, I remember looking in my mom's eyes and going "I wish you were the one that died." and it completely ended everything right there. I have felt bad ever since that moment and I actually get a little teary eyed when Ithink about it. I have never said that again. I don't even know why I said it, maybe because I was 14 and didn't know any better. I honestly think that is the worst thing I have ever done and it is really not even that big of a deal or bad, but it just gets to me. I told my mom sorry about a million times that day too.
 
I was about 14, me and my mom were arguing about me not being allowed to go anywhere because I was caught smoking and at that time, my dad was dead for about 7 years, I remember looking in my mom's eyes and going "I wish you were the one that died." and it completely ended everything right there. I have felt bad ever since that moment and I actually get a little teary eyed when Ithink about it. I have never said that again. I don't even know why I said it, maybe because I was 14 and didn't know any better. I honestly think that is the worst thing I have ever done and it is really not even that big of a deal or bad, but it just gets to me. I told my mom sorry about a million times that day too.

Wow that is pretty terrible. Sorry to hear about your Dad.
 
Wow that is pretty terrible. Sorry to hear about your Dad.

Yeah, it is pretty terrible and I wish I would of never said those words. They are something I can never take back and will live with me. And the fact that my mom does everything with all her power just to make my older, me and my twin sister, my younger brother, and everyone else in my family (everyone in my family besides my grandma is super busy so my mom will help out with picking up/watching their kids) happy, makes it worse because my mom is a really great person and doesn't deserve any bull that is shot at her. But, I guess that is life. I try really hard to do as much as I can for her and be respectful, but sometimes it's really hard to. And thanks. My whole dad being dead doesn't hurt me as bad now because it has been about 12 years now, but I appreciate that.
 
I was messing w/ my hair in an elevator few days back and there were these two little flies that escaped out of it. I felt really bad for keeping them theree unknowingly afterwards, but that's like the worst thing I can think of now.