Charles just frowned, because again, if Merlin had said something, that would be different, but accusing him of manipulating him or lying about this seemed a little unfair without actual proof. He did get that there had been a major violation of trust here, but at the same time, he still did understand why Merlin had done what he'd did. Honestly, Charles didn't know if he would have come clean at all, in Merlin's shoes. He still didn't really love people knowing who he was and what he could do, because they did treat him differently once they knew.

"Then how do you know it wasn't true? I don't mean to remind you of the legends, considering we both know they're not exactly the most accurate things ever written, but I've never read one where Excalibur was given to you because Merlin interfered. It's your sword because you're the rightful king of Camelot, and no one else is supposed to wield it."