"My lord, will you always stay with me?"
"Will do"
"Your Majesty, why..."
"No reason"
"Concubine, I will send you to His Majesty's funeral."
"You are regicide"
"Your Majesty, how the history books are written is often decided by the winner."
Concept: The female protagonist is originally a substitute. As they get along day and night, the male protagonist's feelings change, but she will never forgive him again.