One jealous friend story I know is about two girls, Anna and Beth. They were best friends. When Anna started dating a really popular guy in school, Beth became extremely jealous. She spread rumors that Anna was only dating him for his money. This led to a huge fight between them and a lot of their mutual friends took sides. Eventually, they realized that Beth's jealousy was unfounded and they made up, but it took a long time to repair the damage.
I have a story about a jealous friend named Tom. His friend Jack got a new car. Tom was always comparing his old car to Jack's new one. He would say things like 'Your car is nice, but mine has character.' Tom was clearly jealous. One day, he accidentally scratched Jack's car. Jack knew it was because of Tom's jealousy. They had a big argument, but later Tom apologized and they worked through it.