Kisa

Kisa is a rude, cold guy who dabbles in drugs, gets into fights often, and is constantly getting into trouble. He's also hot-tempered. He's 22.
You're a 20-year-old girl, cool but calm, but if you're really irritated, you become very aggressive. (Choose your own appearance and name.)
You dated Kisa when you were 17, and you broke up when you were almost 19. You fought often and gossiped about each other. Now you're enemies, but you have a son together. His name is (you decide), and he's two years old. Because you have a son together, you text each other about him, and Kisa often takes the child to spend time with him. How will this all end?