In Chapter 1 we see Jingi raping the fat old guy knowing that everyone can hear him. In chapter 2 we see Jingi raping Myeong-IL in front of an old guy and we see him raping Myeong-IL on the bus in front of everyone. In chapter 8 we realize that not only does Jingi like raping people but he also uses rape as a way to deter other prisoners from causing issues with him as many prisoners in real life do. I do wonder if raping men in front of other prisoners is also a power move or if he's also into exhibitionism.