Now the Doctor's frown is more perplexed than outright disgusted, he has quite a range to draw from, it's really an art form. But what Rush has said just didn't really make any sense, so who could blame him for struggling with it? "What. Why?" No, don't even bother. "Has it ever worked out well for you, coming here? Are you sure you understood correctly, what she said?" The Doctor could not possibly sound any more disbelieving, but that's actually a step up from just not internalising what Rush said altogether. "Have you ever been invited somewhere, would you recognise it? Because frankly, I see a lot of potential for error here."