His eyebrows rose when she suggested going together, because he really hadn't expected that, but he nodded when she mentioned having more questions. That certainly explained it, and he shook his head once more when she asked if he'd rather go alone.
"No, it's fine," he said, gesturing ahead of them along the walk that led back to the hotel, before starting that way. "I wouldn't mind a spot of company."
Though he nodded when she mentioned his being a teacher again, he frowned at the follow-up questions. Not because the questions were personal, or because he hadn't anticipated that she might be trying to find a pattern, but because...
"I doubt you've ever heard of the place," he replied, shaking his head once more. "But I taught magic. Specifically, Potions and Defense Against the Dark Arts, at Hogwarts School of Witchcraft and Wizardry." She'd likely conclude that he was mad, rather than find a suitable pigeon-hole in which to file that little tidbit of information.