Hmm? At this point, it's not like she doesn't know that he's an obsessive psycho and that he's only obsessed with her, right? I mean, that was even her plan from the beginning. Since his obsession isn't in the throne but just her, she should realize on some level that ofc he's going to be unhappy if she tries to get him to marry someone else???
It would be one thing if part of her objective with this marriage was to make him turn his attention away from her, but she just seems genuinely confused that he's not happy with her choice?