Play it correctly and you'll understand Annie's logic, which is somewhat explained towards the end of the date.
It's a mutual respect thing which is rather common throughout all adult games, starting with Dating Ariane :D
It's always a bit of a ride on the edge but just like in chess, there are obvious blunders - and flirting with that waitress is one of them ;) Should've been obvious - hence why you save the game before making decisions