It felt good.
When I was starting middleschool I was just in the process or losing weight, I was a chubby kid. I also was the only girl wearing a C cup in 6th grade. I had this friend who wasn't very supportive of me losing weight. Other people would tell me I looked good, good job, etc. She would just make snide remarks afterwards about how I didn't really look much different and that I needed to try harder. Not sure why I continued my friendship with her at the time. I ended up really thinning out, and toning up especially after scoring a spot on the cheerleading team in 7th grade. My friend was even LESS supportive of that, and told me I wasn't as good as the other girls, and that they didn't like me even though it seemed like they did.
Finally after 8th grade ended I was sick of her s***. This was the straw that broke the camels back. I liked this guy who was new, very shy, but really cute and funny. He seemed like he liked me, too but then all the sudden became distant. I wondered why, and come to find out my so-called 'friend' had told him that I was a well known s*** around school and I always f***** the new kid. This really upset especially since I was still a virgin at the time. She then attempted to swoop in and steal him herself but he wasn't really too interested.
It p***** me off so bad that when we started highschool I made it my mission to make her feel how I felt. I pretended to no longer be angry, and acted like I wanted to be friends. I was pretty popular in highschool and was my older brother who was a senior. He had a lot of cute friends and there was one particular guy my 'friend' was interested in. REALLY interested in. In 10th grade we were having a dance to kick off the new year and she wanted to ask him to go with her.
I took it upon myself to flirt with him, since I knew he thought I was attractive. (he'd told my brother this many times and I overheard) He responded heavily and asked me out. We went on two dates and then he asked to take me to the dance. The look on her face when I showed up holding hands with him was priceless. After years of her calling me fat, ruining my confidence, and trying to take my crushes away from me I'd finally got her back REALLY good. We danced the whole night and then went outside to talk where I knew she was. She was standing by the gym entrance b******* about me. We stood across the parking lot where she could see, by his car, and made out.
The next Monday at school she wouldn't even look at me. She ended up confronting me by the end of the day, crying and asking me why I would do such a thing. I blew up on her and pointed out everything she did to me. It was a childish revenge plot, but it worked, it felt good, and I bet she never treated another 'friend' as poorly as she treated me.