Tuesday, Sam and Peter went to a restaurant to eat lunch. After eating lunch, they paid the bill. But Sam and Peter did not pay the bill, so who did?

Why this works

This riddle plays on the expectation that "Tuesday" is just a day of the week, but in this context, it's actually the name of Sam and Peter's friend. The trick lies in the phrasing—when it says "Sam and Peter did not pay the bill," it implies that someone else must have, leading us to the clever realization that the answer is hidden in plain sight: it was their friend named Tuesday who picked up the tab!