What did the three wise men do after they had seen Jesus?

The wise men, or magi, appear in Matthew's Gospel, which says that they then returned home without reporting back to King Herod. Since they were no longer needed in the nativity story, nothing further happened to them. John Shelby Spong (Born of a Woman: A Bishop Rethinks the Birth of Jesus) says that among people he knows in New Testament circles, the universal assumption is that the wise men were not actual people.