Every chair has a folded plaid (wool throw). It is for the legs , not the torso. Draping a blanket over one’s lap is considered perfectly polite and très chic .
As midnight approaches and the bûche is finally served, I ask Madame Sylvie, the 68-year-old secretary of the club who has organized this dinner for 20 years: "Why do this in December? Why not just put on a sweater and have a normal Christmas?"