Why are animals not confused? I don't know what that means.

All the people crossing the line are animals, so animals must cross the line. And this person has not crossed the line, and naturally even animals are not as good as (animals know how to cross the line). Men don't know how to cross the line, so they are not as good as animals. This joke is about a girl's superficial naivety, but in fact, she hopes her boyfriend will take the initiative XXOO have sex with him.