DEAR MISS MANNERS: We have been friends for many years with a married couple and their adult son. They are a very wealthy and socially prominent family. The son and his fiancee, whom we have also known for several years, had a very elaborate destination wedding; we were invited, but had to decline, as we were going to be out of the country. Upon our return home, we wanted to deliver their gift to them, so I called the son. He and his new wife were out of town, so he asked me to drop it by his office and leave it with his private secretary.