"I like the feeling of stability that you have after being in love with the same person for so many years," she says. "I can't imagine how people can tear that apart, that fabric that you've woven together."

"We're like two little weasels," he says in return. "Burrowing under the earth together, protected from the storms."

He beams, she beams. When she speaks, he listens as if the music of the spheres played in her words. When he tosses out a joke, she catches it, delighted, and polishes it with her laughter. Alan and Arlene Alda have been married for 24 years now and this sort of behavior should long ago have disappeared in the usual show-biz lament of disillusion and regret.

He is, after all, one of America's most popular television actors, the star of "M*A*S*H," a show that for nine years has won the battle for the fickle hearts and minds of the television audience. He wrote and starred in "The Seduction of Joe Tynan," and now he is making his debut as a director, in a film that he also wrote and in which he acts, "The Four Seasons." Throughout it all he has been married to the same woman, a woman he met in college when she was a young musician with hopes as bright as his, a woman who is the mother of his three daughters and a free-lance photographer about whom he is clearly bonkers.

By now, of course, there should have been the usual tarnishing of the once-lustrous image -- the tawdry tales in the fan magazines, a couple of screwed-up kids with a lock on all the usual neuroses, the wife abandoned for some more suitable vessel for unsuitable dreams. Instead, there is Alan and Arlene, Arlene and Alan, who set out long ago to make a marriage and to make it work; a thing apart, not to be sacrificed to ambition and other vanities.

Alda is uncomfortable talking about the ways in which they have done this. "It's embarrassing," he says, shifting in his chair, one hand twisting the other, as if to mold his hands into a peaceful pose. "We're not unique. People do what they do. They do it, and that's what they do. So all right. Next."

Not so fast. Most people don't do what they do under the white lights of a profession now known for the aid and comfort it gives to traditional values. Until his daughters reached college age, Alan Alda spent the week in California and the weekend in New Jersey, a schedule that left him "in a permanent state of jet lag. I always had a little buzz on," he says of those days. "At a certain point in the evening I would be watching the lips move, but I couldn't hear the voices anymore."

Alda had almost decided against taking the part of Hawkeye Pierce when "M*A*S*H" was created because of the disruptions it might cause his family. "My reaction was to turn it down," he says now. "I didn't see how we could juggle all of that. I wasn't going to ask my family to do it. I didn't want our lives controlled by the job contract." Now the Aldas spend half the year in California, the other half in New Jersey.

Their three daughters are all in college now; two of them had parts in "The Four Seasons." "You think it's not going to be that hard, raising kids," Alda says. "You think you have something to pass on to them and that's what you'll do. But it's a three-cornered chair - there's you, your kids and the world they grow up in, and each of them is an influence."

"We were fairly strict with them," Arlene Alda says. "When they were 16 and all their friends were getting cars, for instance, we said no car."

"Yeah," says her husband, "but what about the airplane?"

Well, she says, "maybe the airplane was a bit much, but I really think we should have gotten rid of the yacht."

No, her husband says, "they needed the yacht for summers."

They both laugh, secure in the fact that the verdict, after all, is in. They did okay. Their kids are good kids.

Recently the Aldas found a way to combine their two professions. While he worked on the movie, she had a project of her own: taking the photographs for a book chronicling the making of "The Four Seasons."

"What did we learn from the experience?" Alda says. He cocks his head, turning toward his wife. "I don't know, what did we learn?"

"I don't know what you learned; I only know what I learned," Arlene Alda says. She is a short woman with black curly hair; her brown eyes seem to be continually smiling. "For me, there was a good growth. I had to let go. I wasn't there to function as an overly protective wife."

Alan Alda thinks for a moment. "I guess for me it affirmed what I already knew -- that the day is lighter and happier for me when I can be together with Arlene."

It's not that difficult, he insists, this business of being happily married. "If you know what you care about, if you know what you want, you can go get it," he says. "If you're conflicted over the things you want, if unconsciously you have a desire for something else, then you have a strong chance of feeling shortchanged."

"I don't think it's as easy as all that," says his wife. "A lot of how we operate is based on what is happening around us. Things go on according to the fashion. Unfortunately, the fashion now is for change." She describes some graffiti she saw on a wall near Grand Central Station. "It said, 'instant this, instant that.' That's how people relieve pressures now, by changing. For me, I love to eat different things; I satisfy my needs for excitement by tasting something different. But I know the difference between food and people."

"Oh," says her husband, "you mean I'm not a banana in your life?" He laughs loudly, in a staccato burst, then stops as suddenly as he began. "I think there's a lot of pride in making a life," he says quietly. "Not just your work, but your personal life."

Alda's new movie is about the friendship among three couples and the ways in which it deepens and intensifies at the same time it threatens to come apart at the seams. And he is, he says, "delirious" about how it turned out. "I began to understand something about friendship that I didn't understand before," he says. "I think everyone has to go through these stages, from casual to close. In the beginning, in the spring of your friendship, you take pleasure in each other because you're apparently flawless. fIn the summer you begin to see the idiosyncracies. In the fall of your friendship you start expecting things from them, demanding things that you're never going to get, and by the winter you have to decide whether to accept them or start all over again. In a way, we're all doomed to one another. We're very different from one another, and we like to think we're self-sufficient but we're not. And the doomed part is that it's almost impossible to get what we want from each other. You make up in acceptance what you lack in luck."

The character Alda plays, Jack Burroughs, is a man who is charming and sensitive on the surface of his life but who reserves his private self, remaining always at a distance, shielded by the judgments he makes on others. "I took a part of me and satirized it," he says. "The part that I'm not proud of." Not that he thinks he is as aloof and as arrogant as the character he plays. "I'm not that much of a pain in the a--," he says.

"You certainly are not," says Arlene Alda quickly.

Still, he says, "seeing myself up there on the screen liberates me from having to be that person. I can let go. I can . . ." Alan Alda pauses, looking about him as if the rest of the sentence must be hiding in the room somewhere. "It sounded there for a minute like I was going to make a speech," he says laughing. "And now I've forgotten what I was going to say. You see, it's changed me. Although I still love to talk."

So does the character he's made famous, the silver-tongued Capt. Benjamin Franklin Pierce, chief surgeon and razor-edged wit. Alda is still going strong in the role. "We try to show caring in all that brutality," he says. "And in the middle of all that to show some humaneness. I think people are moved by attempts to strike back at the absurdity of life -- I think they recognize their own lives. They want to see health succeed over death, to see real friendship in an existential situation. We came in to tell jokes, and we stayed to touch the edges of art."

Alda began playing Hawkeye Pierce in 1972. The starring role came after long years in acting that included everything from leads on Broadway to more modest roles as a New York cabdriver and doorman. He had some idea of the erratic nature of the profession -- his father, Robert Alda, did a lot of dinner theater in between the two big roles that distinguished his own acting career, as George Gershwin in "Rhapsody in Blue" and the original Sky Masterson in "Guys and Dolls."

Alda never expected "M*A*S*H" to be the success it has been. "We never planned this," he says. "If we had planned it, there would have been enormous disappointments." By the time the show came along, Alda says, he had stopped thinking that greatness could be achieved only within singularly defined channels. "What I gave up was my fantasy of being successful in a certain way. I got looser about my life. That's the reality you're going to get handed anyway, so you might as well make the best of it."

And Alan Alda is, he says, a realist. "Life is more fun that way. You don't set yourself up for disappointments. A realist makes a contract, a deal with people. Let's you and me go and have fun. That way, neither one of us will have expectations that won't be fulfilled."

His wife is "more cynical than he is. I grew up measuring things, testing them and seeing if they were really safe. I think there was a certain caution that came from growing up in the Bronx. You didn't take chances."

"You took a chance on me," says her husband.

Arlene Alda just smiles.