moment of specialized language

I do not know if this counts as a specialized language. I am a big fan of an Asian popular band for more than six years. Once I went to a concert with my friends who love the same band and we were all so excited to stop talking. At that time I accidentally saw my another friend who was not a fan. After a while he texted me that he knew the literal meaning of our fan-talking, but he could not understand what our real topics and what the words' meaning when we used them. I remember our original topic is a picture that one member of the band smiled and walked handsomely with a wheel-up suitcase, which made us laugh for a long time and lead to a term "suitcase photo". From the picture, we talked about a lot of silly cute "accidents" he did, and used words such as dropped hat and degen bag, and we also made some fun of them.
When a group of fans gather together and talk about the idol, we will use the words we use only for the idol-related topics. The origins of the words are quite wide such as Japanese katoons, professional pop music terms, words from old stories, and even terms we created.