Let someone believe they fooled you long enough and they may explain the entire trick.

People who think they have got away with something relax, and relaxed people explain. They elaborate, they take credit, and they reveal the method, often out of a need to be appreciated for their cleverness. Reacting immediately closes that off and leaves you knowing only the small part you noticed. Waiting can be worth far more than the satisfaction of confronting.

When you catch something, consider staying quiet a little longer and simply observing. Decide what you actually want, whether it is distance, a correction, or an understanding of the pattern. Then act once, from a position of knowing more rather than less.