Rich people, take behavioral cues from John Mayer. The introspective troubadour told us last night at Keep a Child Alive’s annual Black Ball that there are some activities that must be curtailed in a recession because they’re too ostentatious. “There are certain things I don’t think I would do right now because it’s not a time to celebrate the country in terms of the economy,” Mayer said. “Even if I had a Ferrari, I don’t think I’d take it out. You know, you’ve got to stay sort of demure.” Learn more about social mores from Justin Timberlake, Queen Latifah, and others by watching our Party Lines slideshow.