He realizes that she does not love him and is only doing so to obey her father.
"How wonderful is a son who obeys his father!"
"And would you rather die than obey your father?"
"And I hope it hurts him long enough that he learns to obey his father."
After a lot of thought and counter-thought, he decides to obey his father.
She had to obey her father, although it made her very sad.
She's my daughter, after all, and a daughter is still required to obey her father.
They voted to obey his father, who had thought him unfit to govern them.
Still, he meant to obey his father and remain right where he was.
She is still young enough to obey her father without question.