One couple has a young son who routinely threatened to telephone the 911 emergency number and report his parents when he didn't like household rules or punishments meted out. Another couple was once summoned by a frantic neighbor to help rescue a cat "strangling in a chair."

But many times, for the 36 married couples within D.C.'s Metropolitan Police Department, the calls are more nerve-racking.

Ann and Robert Tupa, who marked their first wedding anniversary last week, are each assigned to a different sector of the 7th Police District. They work an area police regard as one of the city's toughest, where many calls for help involve domestic disputes--tricky, dangerous situations.

The Tupas say the disputes they deal with on duty make them less inclined to argue at home. "You catch hell at work for eight hours," says Robert. "The last thing you want is to catch hell at home."

The Tupas, like the other couples in the police department, make special adjustments to the pressures, risks, rotating shifts and high visibility of their jobs, factors that some say can make family life difficult for any police officer.

But the officer couples say there is compensation beyond two salaries. "Just talking to somebody who understands is a big relief and takes some of the pressure off," says Eugene Swinson. He and his wife, Dorothy, work in the central communications division at the department's headquarters downtown.

The number of officer marriages has fluctuated over the years. Some couples have separated, others have divorced and in some cases one of the officers has changed jobs or chosen to remain home with children. While precise statistics are not available, some say the number of officer marriages has grown since women joined men in patrol cars in 1972; others insist the increase is a reflection of having more women on the force.

There have never been any District police regulations prohibiting officers from marrying each other. Some say marriages between officers, which have posed no special problems for the department, are inevitable.

"When you have a coed type of situation . . . police officers fall in love and they get married," says Chief Maurice T. Turner. "I think it's going to happen more."

"I don't think the police department is going to try to regulate marriages," he says. "Unofficially, we don't like them working in the same scout car or anything like that."

Leonard and Faith Chappell, married just over a year, met eight years ago at a police recruiting station in a Southeast Washington shopping center and were in the same orientation class as cadets.

They began dating four years ago and after they became engaged, Leonard was injured while making an arrest. His arm was dislocated and he was struck so hard in the chest that his badge was bent, cutting him.

When he called Faith on the telephone, he said simply that "he had been in a 10-33," the police code for officer in trouble. He said it "in a very calm voice so I wouldn't get excited, but that didn't do any good," Faith says.

"It was very upsetting, but it's not as bad as if I weren't a police officer. I know what to expect and I know these types of things can happen," she says.

"Sometimes people ask me, when you hear your wife getting involved in something or yelling for help, which we all do, does it bother you?" says Robert Tupa. "I really don't have much choice. . . . She's doing what she wants to do and she's been doing it a long time." And, he points out, she's been an officer longer than he has--Ann is an 11-year veteran, Robert has four years on the force.

At home, the couples say they try to strike a balance between discussing work and leaving it behind. Sometimes even the best efforts fail. "When we lived on Ely Place SE, the folks used to knock on the door with their police problems, and we'd be off duty , as opposed to calling the working police," recalls Leonard Chappell. The neighbors figured "two police officers live there, hey, they'll get double the service."

For the officer couples, their work tends to promote some other unique situations at home.

When the phone rings at one couple's Northeast Washington home, and the caller asks for "Sgt. R.A. Jenkins," the response is inevitably the same: "Which one?"

Sgts. Romaine Althea and Robert Aaron Jenkins quickly enlighten the confused: She works in the sex offenses branch at police headquarters; he drives a cruiser in the 5th District.

Some may not have the names straight, but they know the faces. With a combined total of 30 years on the force, the Jenkinses say they often are recognized in public, even out of uniform. Driving to a concert at Seventh and T streets NW two years ago, they were greeted by numerous bystanders with shouts of " 'Hey police, hey officer!' " Romaine recalls. "They recognized both of us before we hit the block."

The occasion marked a rare outing together. Wed in 1971, they were able to get the same days off only in the past year. They work the same shift about one week per month.

The Tupas, on the other hand, have identical schedules, though their shifts were not so well matched when they married last year. "I'd be going home, she'd be coming to work, so we'd pass in the hallway," Robert says.

"The police department does not cater to married couples," says Ann Tupa, adding that officials often try to be accommodating. "Our captains came to us" to offer a better schedule, she recalls. The drawback to their schedule is that they often feel constrained to turn down interesting special details that would make their hours differ.

The Swinsons remember when they, too, worked on the street and had to put in long extra hours in court after arrests. Now, working in communications, "it's a lot easier to plan things after work," Dorothy says.

But even scheduling difficulties can be turned to advantage, according to Marty and Bill Clark. "It teaches you time management" and good planning, says Marty, a 2nd District community relations officer. Her husband is a narcotics officer in the morals division.

"Quality time" is a favorite phrase for the Clarks. Most of their free time is spent with children Billy, 11, and Jennifer, 2 1/2.

"Usually one of us is available to do things or to be there" with the kids, says Bill Clark. "Our situation could be very difficult on another young married couple without children, but when you introduce children into it, it works out quite well."

Jackie Knott did find the situation difficult. Knott, a canine officer in the 7th District, met the officer she would later marry in 1969 when she was a legal secretary at Superior Court. They married in 1971, she joined the force in 1975, and the next year they separated. Two years later, they divorced.

"There weren't any real arguments about anything," she says now. "We didn't work the same shift a lot of times and he's one of those people who thought I should be home" when he was.

"A lot of policewomen have come and gone since I've been on," she says. "It's either their marriage or their job." But "I was finally doing something I really wanted to do, I liked it and I didn't want to quit."

Someday, Knott thinks she would like to marry again. And, she acknowledges, "it would be hard to marry anyone other than a police officer."

For Wyllie and Julia Mitchell, who met early in their careers at the police academy and both work in the 7th Police District, the blend of married life and police work is routine.

"We don't know anything else," Julia Mitchell says. "It's the only job I've ever had and the only husband I've ever had."