A joke in A Dream of Red Mansions

This joke is the second joke told by Wang Xifeng. The first joke she told was a lot of "mother-in-law", "grandson" and "granddaughter". In fact, everyone present that night wanted to make fun of Baoyu's relationship with Daiyu or other girls, regardless of you and me, but everyone didn't understand, so they took the opportunity to tell the second firecracker joke. Laugh at the deaf. Everyone didn't understand the first joke (similar to being deaf). So others understood the second joke and were fascinated by Xifeng's wit and laughed. Later, only Li Wan didn't understand. When asked about the result of the first joke, Xifeng was very helpless and responded casually.