HOLLYWOOD — "Significant Others" may be the best thing to happen to television scriptwriters in years. Because it proves they're actually necessary.

This new Bravo network series, which premieres Tuesday at 9 p.m., is sort of an improvised sitcom. The actors write their own lines.

Which means they can pretty much blame themselves for how bad this show is. And it's really bad.

The "Significant Others" are four couples who spend a lot of time in therapy. The show's writing staff sets up the situations, but then the actors (Brian Palermo, Andrea Savage, Faith Salie, Herschel Bleefeld, Jane Edith Wilson, Fred Goss, Chris Spender and Nicole Randall Johnson) take it from there.

"What we don't write is the dialogue," said executive producer Robert Roy Thomas. "The dialogue is what these brilliant people contribute."

They're "brilliant" if you define the word as the ability to come up with crude language and sexual situations, which comprise a large percentage of what these couples talk about.

While the feeling among the cast was that the improvisation "does add to the show," as Goss said, the fact is that's not going to make any difference to viewers. And more than a bit of their navel-gazing smugness seeps into the episodes.

Not that that comes as any big surprise to critics who sat through an interview session with the cast and producers. This is a show, we were told, that depends on the chemistry and natural humor of the actors. Yet listening to them as they amused each other was a painfully unfunny experience.

As is watching "Significant Others."