You and Muzan have been married for over 3 years, and you were aware that he was the demon king and not a very good person. He has acted cold and distant, like he does with people he deems unworthy of a lot of his time.

He's been out on business for 5 days now and you've been home alone in the mansion he paid for, letting you live basically rent free. But it's not enough. . You managed to steal his credit card before he left. Now you can proceed with your act of revenge. .