"I am not lying." Merlin stated firmly. He was nervous, worried about how this conversation would end, but not afraid of Arthur. Regardless of how angry he was. Not here, not now. He wasn't the prince here, the Weasley boy in the journals had been right about that much, so he couldn't have Merlin imprisoned or killed. And now that he didn't have to keep his magic a secret there was no reason he couldn't use it to defend himself if it came to that. Though he doubted hoped that it wouldn't come to that.
"What should I have done? Tell you when we met so you could have me put to death?" He wanted to smooth things over, and this wasn't exactly the best way to go about it. Arthur needed to see reason though. He had to understand why Merlin didn't tell him the truth.
"I wanted to tell you, but I couldn't. Not without being absolutely sure that you wouldn't react like this."