The answers are all wrong.

Yishi said: "What a fool the world is! It is clear that it is a monster, but it thinks it is beautiful. What a fool! It is clear that it is loyal, but it is a delusion. But if you love the sex of others and fish for them, your wife will also eat his saliva. It's so sweet. The way of heaven is good, but the foolish and deluded people don't understand it."

It means that she is obviously a monster but is regarded as a beauty, and she is obviously loyal but is regarded as false. If you abandon your wife, fall in love with someone else's beauty and want to possess her, your wife will eat other people's phlegm and saliva as a sweet treat. Although it is a "ghost story", it has a very meaningful meaning. As the saying goes, you have to pay for the troubles you have caused. "A disease of the heart needs to be healed by the heart."