Sabrina Jess, left with dog Chewbacca, and David Johnson, right, are engaged. Johnson’s co-worker Joshua Hylton, center, lives with them in Manassas, Va.

You’ve heard the story: Guy and girl meet, fall in love, move in together and … get a roommate?

Sabrina Jess, David Johnson and Joshua Hylton have been living in this unusual rental arrangement for the past few months. Jess, 25, and her fiance, Johnson, 34, moved into a two-bedroom apartment in Manassas, Va., in January. Then in June, they asked Johnson’s co-worker Hylton, 25, to move in.

“There was a certain amount of privacy we had when it was just us that we lost,” Johnson says. “It was worth it because we save money.”

High rent costs in the Washington area are driving couples to take on lodgers.

“The main motivator behind any shared living expense is cost,” says Jamie Hornbrook, a senior community manager with Carmel Apartments, which manages 17 apartments in Virginia and D.C.

There are other factors, too. Some couples want a third person around to share the workload around the apartment — it takes two to tango but three to put up drapes — or if they have an extra room they aren’t using.

“I prefer to have someone,” Jess said of living with Hylton. “I enjoy the fact that we are making use of the space that we have and being efficient with things.”

Susan Segal, a D.C.-based couple’s therapist, says that, with her clients, the extra singleton often is a family member who needs a place to stay. “A couple I was working with had the wife’s sister move in with them,” Segal says.


Three’s a Crowd

Living with a third wheel can be tricky for both the couple and the single person. How does a couple’s relationship fare with another person living in close quarters?

Segal says a living situation like this can end up straining a couple’s relationship.

“You give up a certain amount of privacy,” Segal says. “You may lose a lot of important intimacy.”

Segal advises roommates to make sure everyone is not only respectful of one another’s physical space but emotional space as well. “The single person must realize that the couple needs time and space to be a couple,” Segal says.

It’s not just space that’s important; there’s timing, too. Couples and singles whose schedules are too similar can start to cramp one another’s style.

“I do keep to myself,” Hylton said. “I hang in my room, and when their door is closed, I don’t bother knocking.”

Schedules play an important part in it, Hornbrook says.

“If someone travels a lot or they have opposite work schedules, that could really work in their advantage,” she says.


Even Steven?

Equally important: How do you split rent, chores and personal space?

Johnson, Jess and Hylton first tackled the question of rent. Rent becomes more complicated with a couple who are sharing a room but taking up more than half of the common space, making it unclear if the single person should pay half or a third.

Johnson and Jess decided Hylton should pay one-third of the rent. He and Jess “don’t consider ourselves a single entity,” Johnson says, explaining that most of Hylton’s space is his room. “The number of rooms you take up is how much you should pay in rent.”

Hornbrook says there are a variety of ways renters in this situation divide up rent. She’s even known renters who measure the square footage that the single person will be using to determine their share.

“They’ll base it on the amount of space that a person is actually living in — it can get kind of crazy,” she says.


Give a Little, Get a Little

Hylton, Johnson and Jess have ironed out most of the kinks in their trifecta.

One simple step they took was to make sure they didn’t annoy one another too much. That means normal roommate stuff such as keeping up with chores (everyone agrees Hylton needs to take out the trash more) and respecting personal boundaries (“I have to wear pants around the house now,” Jess jokes).

And everybody gets something out of the situation, beyond cheaper rent.

“I do feel safer,” Jess says. “I’m convinced that every weird sound I hear is someone creeping around in the yard. It’s nice to have someone extra around.”

Couples therapist Segal says that having another person around can nip lovers’ quarrels in the bud. “They can temper any arguments or issues the couple has because they don’t want to argue,” she says. “Sometimes it can defuse a couple’s issues so they behave better.”

A note to the solo lodger: If your couple roomies are arguing, never take sides. That’s pretty much guaranteed to make things worse.


Try, Try Again

Johnson knows firsthand that a living situation like this can be emotionally sticky. Before he met Jess, he lived with his now-ex-girlfriend and his best friend. That girlfriend left him for the best friend/roommate. The two are now married.

But Johnson has given it another go, and he doesn’t see that failed living situation as a reason to avoid living with an extra person. Things with Hylton have been working out so well, the trio don’t plan to break up any time soon.

Says Johnson: “Jess and I are contemplating buying a house, and we’re taking him with us.” MATT RAZAK (FOR EXPRESS)