1. The Wi-Fi password.
My roommate owed me $10 for the internet but gave me $7. So I changed the Wi-Fi password so it was 10 digits long and only gave her seven of them. I told her she could have the rest when she paid me.
2. The lightbulb thief.
When my boyfriend and I got into an argument, I took all of the lightbulbs from our apartment while he was taking a walk to cool off. I took the one out of the oven, and I even took the vacuum cleaner because it had a light. I left with a bag full of lightbulbs and stayed at a friend's house that night.
– Jenna Allen, Facebook
3. The melted blue cheese.
My ex thought it would be funny to cheat on me so I hid all types of mouldy blue cheese in his car. He only used his car at the weekend, so when he got into it, the cheese had been melting in the hot weather for about a week.
4. The split trousers.
One time my friend said something to annoy me, so I snuck into his house and unstitched all of the crotches in his trousers so they were fragile and kept splitting.
5. The toilet water.
When I was in fifth grade my entire family pissed me off. I had to iron everyone's clothes so I filled the iron with toilet water.
– Carline Joseph, Facebook
6. The dog brush.
When I was in middle school I hated my mum's boyfriend, mostly because he hated my dog. One day, when I was home alone, I took his toothbrush and let my dog lick it.
7. The plus-one.
I went to my ex's wedding as the best man's plus-one.
8. The surprise delivery.
This fuckboy that I know kept sending me nudes on Snapchat, so I took screenshots of them, printed them out, and mailed them to his mother. Now he doesn't have a phone.
9. The orange juice.
A co-worker I didn't like drank my orange juice and said I should have put my name on it. The next day, I gave him his own "orange juice". What he didn't know was that it was water mixed with mac and cheese powder.
10. The wikiHow.
Once I sent my friend a wikiHow article called "how to be a good friend" while we were fighting.
11. The last roast potato.
Once, when I was younger, I cut a hole in three pairs of my sister's socks just because she wouldn't let me have the last roast potato.
12. The hacked Instagram.
So I recently discovered that my ex–best friend had been talking bad about me to everyone who would listen. So I hacked into her Instagram and deleted every single post she had ever posted.
13. The glitter revenge.
After I broke up with my ex, my friends wanted to get revenge when helping me move out, so they sprinkled glitter all over his bed and couch. They also sprayed his straws with Lysol.
14. The proof that pettiness comes in all sizes.
This guy I used to date in high school thought I was jealous of his new girlfriend (I wasn't), so he started to tell all these crazy, exaggerated sexual secrets about me. So to reciprocate, my petty ass decided to tell our class of 452 how small his penis is. Now he's known as "Baby Dick Davis". Bam, bitch.
15. The mosquito bite.
I saw a mosquito land on my friend's arm but she was being annoying earlier that day so I just watched it bite her. It was so satisfying.
16. The dream betrayal.
My friend once had a dream that I started dating her ex-boyfriend. She wouldn't speak to me for a week afterwards.
17. The unrequited love.
When I was in fourth grade, I remember I liked this boy but he didn't like me, so when he was playing his Xbox and about to beat a level, I unplugged the console and he lost all the data.
18. The High School Musical inspiration.
My boyfriend had been cheating on me and I couldn't just break up with him like a normal person. So while I was out with my friends, I sent him a link to the music video for "I Gotta Go My Own Way" from High School Musical and then blocked him on everything.
19. The explosion of petty.
My boyfriend loves his morning energy drinks. If he pisses me off I'll shake the shit out of them so they explode in his face.
20. The evil step-mum.
I was staying the weekend at my dad's house and I was suffering the worst kind of cold imaginable. All I wanted to do was sleep, but my step-mum (who had never been very nice to me) demanded I get up and do chores (that were not my chores to begin with). When I set the table, I secretly licked every inch of her plate, knife, and fork to ensure she would get sick and suffer the same cold I had.
21. The Facebook revenge.
I found out the guy I had been seeing had been having full-on relationships with four other girls. He was actually homeless and stayed with each of us on a different night during the week. So, all us girls connected on Facebook and met up for drinks and dinner and sent him a picture at the restaurant, flipping him off. We then posted it on Facebook and tagged him in it.
Note: Submissions have been edited for length and/or clarity.