Envy, Resentment Across Marriage Gulf : Lifestyle: The schism between married couples and singles may be widening, as each glares at the other across the social divide.

On Bad Date No. 417, Karen Altman stared across the table at a man she liked about as much as a flat tire and thought of her friend Eileen.

Eileen and her husband, Dave, pushing their son and daughter on the swing set behind their split-level home. Eileen and Dave planting a vegetable garden in their back yard. Eileen and Dave dodging their children’s bikes as they walked their dogs.

Images flashed through her mind like snapshots from a family photo album. The same kind of album Altman thought she would be assembling by age 35, only to find herself instead forcing down dinner and idle chatter, wishing she were alone in her apartment with her dog, Barney, and a rented video.

“It’s not that I’m not happy for them,” she says of her married friends. “It’s just that at this point in my life, I think I should be married, too. I start asking myself, ‘What’s wrong with me? What do they have that I don’t?’ ”

Dispute it all you want, for better or worse the world is divided into two groups: single and married. It’s a case of you say tomato, I say tomahto--or maybe you buy soup for one, I buy econo-size. And much as they hate to admit it, when the twain meet, single and married friends are finding that alongside the expressed support for each other’s lifestyles is often an undercurrent of envy and resentment.

Mention married people to 60-year-old single Bob Kaufman and the words unleash a torrent of humorous barbs.

“Married people?” he says with a good-natured chuckle. “Take ‘em all out and shoot ‘em. They’re cowards, they’re traitors. Some of the more conservative (singles) among us say we should only shoot the happily married ones. The others serve as an example. They make the rest of us feel better.”

Mention single people to his friend Ed Sommerfeldt, happily married for 22 years and the proud father of two, and you’ll hear another side of the story: “The first word that comes to my mind is lonely.”

But the tension between the two groups is often more circumstantial than intentional, says Neil Bernstein, a Washington psychologist who works extensively with couples and singles.

“I think the most common reason for the slowly developing schism is time pressure. When you get married and have kids, you only have so much time available. Something’s got to give. If something’s going to be sacrificed, it’s going to be the old relationships,” he says.

But Richard G. Berman, author of “Single in Baltimore,” puts the blame elsewhere. He faults society for still enforcing the notion that it’s a couples-only world.

“We have a culture that encourages marriages. If you’re not married, it’s not OK,” says Berman, who counsels singles.

Statistics show that more people are walking down the aisle than going it alone--with married people outnumbering singles by some 33 million in U.S. Census Bureau figures from March, 1989.

To see how that translates into attitudes about single life, all you have to do is look at the interest generated in the bachelor status of Supreme Court Justice David Souter during his confirmation hearings last fall. Or turn on the television to a recent episode of “thirtysomething” and listen to Ellyn describe life before getting engaged:

“You know the worst thing about being single isn’t being alone,” she tells her psychiatrist. “It’s the way everyone perceives you.”

For married and single friends, what complicates their relationships is often the perceptions--or misperceptions--each has of the other.

“Long-time marrieds and screenwriters and other deranged types are sure that singlehood means beautiful sports cars and lovers, all of which perform superbly. And single people too often feel that married people have it made. They have this other person who’s going to make life OK,” says Berman, whose latest book, “Single in Washington: The Reality and the Resources,” is due out this spring.

Having attended the weddings of eight close friends in the last few years, Altman has started feeling as she did in fourth grade when she stood drearily on the sidelines, the last person picked for kick ball, watching her friends charge onto the field and forget her in their enthusiasm.

“We don’t tend to talk about the same things as we used to,” she says of her now-married friends. “We don’t compare notes on dates. It’s me calling to find out how their husband is, how the children are.”

On the flip side, Gayle Streimer, who is married and the mother of two, says there are parts of her life single friends don’t understand.

“Most single people think that if you’re married, you’re being supported by your husband. I feel a little defensive about that. I do have my own credit cards and my own checking account. I have to prove to them that I’m not being taken care of,” says Streimer, a toy company sales representative.

Even siblings, it seems, are not immune to the growing alienation that can occur after the marital status of one changes. When her first child was born, Streimer noticed a tension in her relationship with her older, single sister in California.

“At the beginning, there was real jealousy. She was supposed to be the one to get married first and have children, by everyone else’s standards,” says Streimer, 31. “And sometimes, I’d get jealous. . . . Men send her flowers or airline tickets to Hawaii. It’s not unusual for her to go to Tahoe for the weekend or sailing to Mexico for the week.”

Meanwhile, she says, “I’m schlepping the kids to gymnastics and birthday parties or the baby sitter cancels and we can’t go out to dinner on Saturday night.”

Women generally work harder than men at sustaining friendships and mourn their loss more openly, Berman says. What often sustains men, he says, is that many times they invest half their lives in their marriage, saving the other half for their career. “Women,” he says, “are taught to immerse themselves in their marriage.”