Mme. Verdurin, who asked: “Have you ever met the Duc de Guermantes there?” “Ah! That I don’t remember.” “Oh!” said Mme. Verdurin, “you don’t know the Duc de Guermantes?” “And how should I not know him?” replied M. de Charlus, his lips curving in a smile. This smile was ironical; but as the Baron was afraid of letting a gold tooth be seen, he stopped it with a reverse movement of his lips, so that the resulting sinuosity was that of a good-natured smile. “Why do you say: ‘How should I not know him?’ ” “Because he is my brother,” said M. de Charlus carelessly, leaving Mme. Verdurin plunged in stupefaction and in the uncertainty whether her guest was making fun of her, was a natural son, or a son by another marriage. The idea that the brother of the Duc de Guermantes might be called Baron de Charlus never entered her head. She bore down upon me. “I heard M.