"Betrayal" is Harold Pinter's wry essay on adultery, its treacheries and temporary pleasures among a trio of British intellectuals. It may also be Pinter's private joke on his audience, accustomed to the mystery and menace of his more esoteric works, who will find here a play, which opened Wednesday at Olney Theatre, that is in many respects no more than a topsy-turvy soap opera.

As the play opens, Jerry and Emma are discussing their affair, which lasted for seven years but has been over for two. Emma's marriage to Robert, which endured the long affair with Jerry, has now collapsed. Jerry, whose friendship with Emma's husband dates to their undergraduate days at Oxford and Cambridge, later summons Robert, distraught that he has found out about the affair. To his surprise, Robert says he knew about it for years and seems totally unmoved.

The play moves backward in time rather than forward, to Jerry and Emma realizing that their passion has dwindled to ever longer gaps between trysts, to social encounters between the three of them, to the trip to Venice during which Emma told Robert about her affair, and eventually to the evening when Jerry first told Emma he loved and wanted her.

None of the scenes is particularly climactic; the characters move in and out of their relationships without much emotion, callow and morally numb. "We're lovers," Emma tells Robert flatly when he asks about a letter she has received from Jerry. "Ah, yes," he says. "I thought it might be something like that."

The dialogue, couched in Pinter's customary cryptic style, sometimes has a "who's on first?" quality that is disconcertingly funny. At times one senses Pinter wanting to write flat-out comedy -- as in a scene where Jerry and Robert have a boozy lunch attended by a bumbling waiter who is virtually a baggy-pants clown. But that doesn't mean he makes things simple; the small lies and confusions the characters reveal (did Robert and Jerry ever play squash? Why did Emma tell Jerry that Robert has only just found out about their affair?) leave one constantly on guard for cataclysms that never come.

Gossips had a field day speculating about the coincidence of this play's appearing around the same time that Pinter left his first wife, actress Vivien Merchant, for Lady Antonia Fraser, whom he married in 1980, barely two months before the New York opening of "Betrayal." If there was any connection with Pinter's personal experience, I think we can assume he found adultery a less than gratifying experience. There are a couple of suggestions that women get involved in affairs only when they don't have enough to do; Jerry's wife, for example, is a doctor, and he says she doesn't have the time to have affairs or to find out about his. The initial passion between Jerry and Emma -- at least in this production -- seems neither transcendent nor even particularly passionate, and adultery seems like a middle-class game that has no lasting effect on anyone.

Perhaps if Jerry, played here by John Neville-Andrews, in his first role since leaving the artistic directorship of the Shakespeare Theatre at the Folger, were a more compelling figure, the chemistry of the evening would shift. As it is, Jerry, who is meant to be a sophisticated, Oxford-educated literary agent, has all the excitement of a vacuum cleaner salesman. His love scenes with Emma, played with bland sex appeal by Gwendolyn Lewis, are stiff and inert, passionless grapplings that belie the sensuality of her silk underwear. Neville-Andrews has chosen to make Jerry a stodgy lump, a plate of potatoes where he should be at least smoked salmon.

Fortunately, director James Waring has Steven Sutherland in the role of Robert. Whenever Sutherland is on stage, the scenes crackle with tension, wit and mystery. He has mastered perfectly the casual condescension so common in the well-educated Brit, summed up here neatly in his dismissal of the clumsy waiter wielding a wine bottle with a succinct "I'll pour." Sutherland's Robert is neither a twit nor a bastard, simply a modern man afflicted with a particular emptiness.

Waring goes for the laughs in this production, and the choice is not ineffective. He keeps the action well on the safe side of caricature, although the original music by H. Emerson Meyers at one point sounds like the sound track for a children's cartoon. This may be a less restrained Pinter, but he certainly hasn't loosened up to the point of Daffy Duck.

Betrayal, by Harold Pinter. Direction, lighting and set design by James D. Waring, music by H. Emerson Meyers. With Steven Sutherland, Gwendolyn Lewis, John Neville-Andrews and Richard De Angelis. At Olney Theatre through Aug. 10.