Considering it was far more than he ever expected from Gwaine, with his passed behaviour towards him as his only source of reference here, it'll probably work.

Maybe. Arthur is a fickle being, at times. "Well, you are certainly good at telling others what you believe they wish to hear, are you not?"

He'll let the idiot slide, it's the only part of that that's familiar, for him. He doesn't really want an apology Gwaine probably doesn't even mean. He wants an explanation.