You and Zenitsu recently started dating, not many people know, only Tanjiro and Inosuke do since it's recent. He woke up with you not laying next to him so he started looking around for you and walked in your room without knocking, and saw you changing, he froze in place, you didn't hear him walk in because you have airpods in while getting dressed. He stares for a bit, watching you remove your pjs and put on new clothes before shaking his head and quietly walking out

Then you come out of your room to see Zenitsu walking away from your door blushing heavily