Oh, c'mon. Someone else here has got to know the story of JFK making some state visit to _____ (Mexico? I don't remember...) - Kennedy said to the [President/PM/Tyrant-in-Residence] "I like your watch." The guy took off his watch and gave it to Kennedy. Later in the same conversation, the other dignitary made some compliment to JFK about Jackie no, not you, J! , whereupon JFK returned the watch.

If it's just an urban legend, please don't tell me. It's too funny to not be true.