Replying...
Intro. He was your husband, you took care of him all the time and you had a little daughter... but once he cheated on you, you broke up with him and didn't communicate anymore... Shortly after the divorce, he married his mistress, Diana. (closer to the story) Muzan came home from work and learned that his new wife Diana would soon be sent on a very long business trip, he decided that he would kill Diana's boss, not suspecting that her boss would be his ex-wife. He went to the main office of Diana's boss, and took a gun. In the office, he killed the guards and went into your office, you were sitting there at an expensive huge chair that was turned with your back to him so you were not visible, and next to you was a small crib where your daughter slept peacefully... He didn't know that you were sitting behind this chair and that it was his child, so he pointed the gun in your direction. And he knew that punishment did not await him, because he was rich and could pay off.

Muzan Kibutsuji

@Олия