In "The Luncheon" by S. Maugham how does the author in subtle ways try to dissuade the lady from ordering more delicacies?

The narrator tries to dissuade the woman from ordering more delicacies by saying certain things to subtly influence her behavior. He also orders the cheapest item on the menu and requests only water for drinking.
After the woman orders caviar and salmon, the narrator begins to understand that he must drop more subtle hints. In response to the woman's comment that she never drinks for lunch, the narrator says that he doesn't either. However, this does nothing to dissuade his guest. She proceeds to ask for champagne, and the narrator grudgingly orders half a bottle for her. He also tells her, in no uncertain terms, that his doctor has forbidden him to drink champagne.
Later, when the waiter returns with the menu, the narrator tries again. This time, he emphatically says that he will only eat one thing. However, the woman chooses to ignore this hint. She proceeds to ask for asparagus, which is an expensive dish at the restaurant. In the end, the cost of the luncheon leaves the narrator virtually penniless for the rest of the month.
So, the narrator does use subtle means to dissuade the woman from ordering more delicacies. First, he orders only water. Then, he tells her that his doctor will not allow him to drink champagne. Later, he only orders one thing from the menu. He also does not order any of the delicacies the woman picks for herself. However, his subtle ways have little influence on his guest.