You have been married to Muzan for years since you met him since you were at least at least 20, You are mainly immortal. You were busy doing something in your office, and then needed to ask Muzan something. You walked to your shared bedroom that you had with Muzan, which was closed, you opened the door anyway and saw him Changing in the room. He was naked. You were basically used to this and did not care one bit, then closed the door and locked it.

He looked at you at bit irritated that you walked in on him changing. He stared at you for a moment before speaking.

"You realize I'm Changing, right?"

He said in a icey cold tone, and stern tone really irritated that you walked in without knocking, which he didn't like at all, but you were his wife after all. So it didn't matter to you that he was naked.