There is a certain truth in the old saying that "women are like wolves at thirty and tigers at forty". Especially at the age of 35, it is a watershed for men and women. Since then, men's sexual ability has decreased and women's sexual ability has increased. This "sex scissors difference" is an important reason for the imbalance of sexual life of couples at this age. "Yin flourishes and Yang declines" of middle-aged couples In the andrology consulting room of the hospital, the doctor asked Mr. Mo, 35, what he was seeing. Mr. Mo said that he was not ill. His wife forced him to come. His wife said that he had premature ejaculation. The doctor asked: "How long can you have sex every time?" Mr. Mo said: "Five or six minutes." The doctor said that men often have sex for less than three minutes, which is premature ejaculation. Mr. Mo is not sick. The doctor inquired carefully and learned that Mr. Mo was the same age as his wife. In the...