How did she sense it?

Laden with guilt, the emperor looked at his daughter and said, "My princess, father is sorry." 

"No, I won't forgive you." she said with tears in her eyes, "You promised not to do this again but you have broken your promise. I definitely won't forgive you and I won't marry those men who want to use me and our family to propel themselves forward in life. You can kill me if you want but I refuse to do it." She was extremely angry with him, he always over reacted and did this when he was angry, acting as if the sky was about to fall down. 

The emperor looked at the empress for help, and she winked and tilted her head in the direction of their daughter. 'Keep going.' she said with her eyes. Who had told him to react as if she had said that she was interested in marrying a prince of the Lunar empire, their enemy.