Why did bud insist on seeing the man's teeth?

Bud insisted on seeing the man's teeth as a way to assess his character and trustworthiness. In the context of the story, Bud had learned that a person's teeth could reveal a lot about them, including their care for themselves and their honesty. This unusual request highlights Bud's cautious nature and his desire to protect himself in a world where he is often vulnerable. It also serves as a metaphor for deeper insights into people's true selves.