Juliet: Then have my lips the sin that they have took. Romeo: Sin from my lips? O trespass sweetly urg’d! Give me my sin again. Juliet: You kiss by the book. Shakespeare uses the structure of these lines to explain the great differences between feuding families. demonstrate the playful affection of a new relationship. persuade readers that kissing is sinful behavior. contrast Romeo’s impulsiveness with Juliet’s calm.