The best thing about Whit Stillman's Metropolitan is its subject. It's about the new generation of upper-crust Manhattan-WASP preppies: kids who wear tuxes and prom-night dresses to their small, cliquish gatherings, even though the posh, sophisticated evening wear no longer has any relation to the culture in which they live. For a while, as the members of the self-proclaimed ''Sally Fowler Rat Pack'' sit around living rooms debating the fine points of Jane Austen or chewing over such matters as who's going to escort whom to the next deb party, the picture has a likable, skewed formality it's Revenge of the Nerds in black tie. The most exotic thing about the characters isn't that they're rich, or that they come from socialite backgrounds. It's that they seem untouched by pop culture. They might almost be high-school thespians who had been cast in a Noel Coward play and then, when the play ended, just kept on acting that way.
Two-thirds of the way through, however, we learn that the characters do have conventional outside lives. Their mildly self-deprecating, oh-what-an- anachronistic-breed-are-we banter is just a pose, an occasional shtick. (The movie is set during Christmas vacation, when they have nothing to do but hang out.)
The fact that Stillman withholds this information for so long feels like a cheat. Instead of a full-bodied comic portrait of the coming-out-party set, Metropolitan offers a thin, cartoon version. Then it uses that cartoonishness to make everyone on-screen seem irresistibly cute. Stillman writes some good lines, but except for Nick (Christopher Eigeman), a bitchy, epigram-spouting bon vivant with a heart of gold, he doesn't really create characters. And his worldview seems quite chaste for a movie about contemporary young adults. In this film, sex is shoved so far to one side that we can't tell whether it's the characters who prefer it that way or Stillman himself. Metropolitan has a great subject, all right, but it treats that subject with white (kid) gloves. C+