[She breathes out and only looks up at him once he is standing between her and the secret, once she no longer has to look at it.
And while he may not be asking anything directly, she still bites her lip, takes that prompting "hey" to mean that he wants to know what the words are about. He is trying to help her... she owes him some kind of explanation.]
... I told you before that I don't want to go back. That... that is why. I went to King's Landing because I was engaged to- to the prince, but he's the king now. I thought he and the Queen Regent [Cersei, Joffrey's mother] were good people.
But they branded my father a traitor and executed him. Now they keep me hostage, for my brother is fighting a war against them. [The more she speaks, the easier the words flow, though with no less emotion.]