Oh, good. He was really starting to worry he was going to get thrown off if she kept it up. He doesn't loosen his grip, not trusting her not to start again. "How many times...?" he repeats, confused. Who would have -- oh. Oh. "Shit, you're that -- that TARDIS, aren't you?"

Not someone he wanted to run into anytime soon. He turns to try to look down and behind him, and gulps. The worst part of flying, he's discovered, is letting go and trusting he can actually do it. "I can't," he informs her tersely.