So long as Uther wasn't looking. Or have you forgotten that? You'd disobey him so long as you didn't have to do it to his face.

[And for all that she spent a year and more lying to them, she's still so bitter about that. He wouldn't stand up for her or the things she believed in, he wouldn't even speak out against Uther's awful decisions, and it fell to her every time to disagree and argue and be punished.]

You aren't my friend, Arthur, and you were a poor one when you were. All my life, there has only ever been one person who's shown me truth and compassion, and it wasn't you. [She spits it out like she's disgusted with him.]