In contrast to Arla's smile, David frowned severely, hard to tell whether the expression was genuine or put on as a show. "Here now," he said, shaking his head. "None of that." It wasn't that he would dare to say that it wasn't true -- he'd heard whispers along those lines, when he'd first arrived, mentioned to he'd-forgotten-who that he was taking up quarters down in the basement. But it was always worse hearing anything like that coming from the person themselves, it made his heart ache, however corny that sounded.
He touched her shoulder with a gentle hand - briefly, because he needed both hands to keep himself balanced for any length of time. "I know for a fact that at least one confused Japanese kid thinks you're the only person here - myself included, I think," David wrinkled his nose at that, "who can actually teach properly." He pushed away from the side finally, treading water lightly to keep his head above water. That was on top of his personal disbelief at the idea of Arla looking bad, even with her amphibian traits. She didn't seem particularly comfortable with that genre of compliment, though, so he left it at that.