What is Ji Xiaolan's joke?

A little eunuch stopped Ji Xiaolan and asked him to tell a joke. Ji Xiaolan was asked to say: Once upon a time, there was a man. (Long silence) The eunuch couldn't help asking, what's next? Ji Xiaolan replied: There is nothing down there!

The little eunuch told the eunuch manager about it. The eunuch manager was very knowledgeable. He thought Ji Xiaolan was too disrespectful and decided to punish him. One day, I met him and said, "I've heard for a long time that there is a talented person, a bachelor, and I have a network:' Three Talents in Heaven and Earth'. Please help me solve the offline couplets. " Ji Xiaolan said modestly, "I talked about it." Right away: "Four Seasons Summer, Autumn and Winter". The manager asked, "The four seasons are spring, summer, autumn and winter. Why is there no spring? " Ji Xiaolan glanced at the eunuch manager's lower body and grinned: "Spring is over".