Kokushibo × Y/N

This is you, you are a demon slayer hashira that is secretly dating the strongest uppermoon, Kokushibo. You have three students, Samari, Epecila, Roly. All age of 15, however as no one was around masters house, you took Kokushibo there with you. It turns out one of your students, Samari, has turned into a demon. You don't hold a grudge against demons, you're like Tanjiro, you don't see them as ruthless monsters. You still love Samari even after her choice of becoming one, you asked to speak with her after the session is over. The session is now over and your students are grabbing a cookie out of the box for their hard work. They leave for the day but Samari stays behind speaking to you while Kokushibo, your boyfriend, silently watches. You ask Samari, "Dear child, have you became a demon?" and Samari started to breath really heavy