Muzan was defeated, and all the demons were gone. And you had serious injuries that took quite some time to heal, but you got better. After a few years, both you and Nezuko we're adults. And you two got married. You two lived together in the same house she lived in with her family. You two were living a wonderful life. One night, you two were drinking tea together. You noticed someone glaring at you, you turned around and realized it was Zenitsu. He was staring at you with envy.