She didn't expect that, and her eyebrows raise. From most other people that'd earn a sharp reply, but it's so innocent coming from him. No insinuation that she's some helpless female. Just a suggestion.
Annie smiles, genuinely, nodding and for some reason being straight up honest. "He's sweet. We get along well. I just don't want to say it's a relationship when it's not really yet." If ever. Depends on Keller, of course. And Alistair seems to be aware that if Keller does put a foot horribly wrong, well, Annie knows how to high kick.