Ex-Husband changing the story after it was selected makes no sense. ch 76

I don't understand why she let the ex-husband write something for her drama. But more than anything I don't know why they let him CHANGE the story they had selected. Like they selected him for a specific story, they decide to continue to work with him when they see its him and then he just goes and like "actually it would be better if we change this part to this". it's no longer the story they wanted to select. She doesn't want to play a mistress like role. And she was the one choosing the story. So why did they let him change it when he is not the boss? and she has deciding powers? makes no sense. And change it to somethign that is so obviously a reference to what happened between them.