2014. The main reason why Nichkhun beat up Changmin was because Song Qian had previously posted a photo on Weibo of eating delicious food out. The most important thing was that in the photo, apart from the food and Song Qian, there was also Changmin. So after Nichkhun saw the photo, he became very angry and jealous, so he went out and beat Changmin violently, thinking that he had secretly met his girlfriend.