Blinking down at their linked hands in confusion, he glanced up at Arthur, frowning slightly. Stilling as the words registered with him, gaze growing wide at the idea that he wasn't upset, or even scared of him, of his magic, like he'd thought he would be.
Opening his mouth to argue about why he'd kept it from him all these years, it had been for his good, both of their's really. Though Merlin shut it just as quickly when Arthur told him he was in love with him. "You're..."He started, staring, flabbergasted, at him for a moment before breaking their clasped hands. Curling his fingers around Arthur's cheek's he leaned in, snogging him for a moment.