Ok, I perfectly understand why he married the Duke’s daughter. He literally did it to stop the rebellion! The MC was being a bit unfair when she said he did it thinking of himself. He did it for his people! Any good Emperor and Empress always has the people’s well-being in mind. She isn’t really trying to understand his reasonings. Asking her to wait was a bit ridiculous, I will admit. I think they just need to let each other go. Love doesn’t always work out. This is just one of those unfortunate situations where everyone ends up hurt. It’s no one’s fault, and I think it is very naive to say he was a bastard or “coward” for choosing to save his people.