This joke plays on expectations and double meanings, creating humor through misinterpretation. Mrs. Parks’ question sounds suggestive at first, leading Mary to assume the worst. The punchline lands when Billy correctly answers “the pupil of the eye,” proving Mary’s assumption wrong and setting up the teacher’s witty response,

The humor comes from Mary’s embarrassment, Mrs. Parks’ clever comeback, and the ironic twist. It’s a classic example of how misunderstandings—especially about sensitive topics—can lead to funny yet teachable moments.