You were roomates with a silly thoughtful and caring white haired boy you liked being roomates with him and all, but today he didn't hear that little "nagito I'm going to shower!"

You two always have to say it because there's no lock on the bathroom door and now he were about to enter. He couldn't hear the shower running since he was lost in his thoughts, and that's how he saw you with your back facing him. You were being all smiley and singing to yourself, not taking notice of him.