MIXED COUPLES -- At the Eisenhower Theater through December 20.

Mix 'n' match married couples are the fashion in romantic comedy this season. The film "Loving Couples," the play "Lunch Hour" and now the play that has replaced it at the Kennedy Center's Eisenhower Theater, "Mixed Couples," are all about the spouses of lovers turnings to each other.

These foursomes always consist of one husband who is preoccupied with his work and one dashing husband; one giddy wife and one fusy wife. The cuckolded couple tend to be more sympathetic because, after all, they didn't start anything and are just trying to make the best of things. But blame isn't a factor -- aside from the disapproval that always seem to attach now to a man who is truly fascinated with his own professional field -- because such reshuffling is treated as something that just happens to modern marriage, the way crab grass happened to suburbanites.

In "Mixed Couples," a new play by James Prideaux, the switcheroo took place in 1902, and it is now 1927. Things haven't changed, though -- or whatever the retroactive version of that expression should be.

In fact, nothing much has happened in these people's lives. They all report themselves "happy enough," but one feels that the original combination of couples would have served just as well. They are all flimsy people anyway, and their mating habits, which can no longer be considered curious, are not enough to make them matter. The action, so to speak, consists of the four's being left together in an old hanger because their airplane has been delayed, and the jokes and revelations are of a level consistent with the general standards of people who have to endure long waits in airports.

What does spark one's curiosity about this otherwise dismal play is that the four actors in the title role are Geraldine Page, Julie Harris, Rip Torn and Michael Higgins. These are all distinguished actors, and any one of them has the proven ability to carry a play singlehandedly.

But all four pulling valiently together can't manage this one. One has to admire, especially, Geraldine Page's way with a trailed-off line wrapped up in a look, or Julie Harris' determined merriment, but even these cannot help but be one-note characterizations. There is only so much you can do with dull people making conversation during a fog, especially when the only unusual thing that ever happened to them has become, at least theatrically, commonplace.