Why in the book did a naked 16-year-old boy on the beach let a curious woman in a crinoline touch his genitals?

It seems like you're referring to a specific scene from a literary work, potentially one with controversial or provocative themes. Without knowing the exact book, it’s hard to provide a precise analysis, but scenes like this can often serve several narrative purposes. Such moments may explore themes of innocence, curiosity, vulnerability, or the complexities of sexual awakening. Authors might use shocking or unexpected events to challenge societal norms, provoke thought, or illustrate the contrasts between childhood and adulthood. They could also serve to highlight the exploration of identity or the consequences of desire. If you can provide the title of the book or more context, I could offer a more tailored analysis or explanation regarding that specific scene.