Three years ago, William Mamel climbed a ladder in Margaret Sheroff’s apartment and fixed a malfunctioning ceiling fan. “I love that you did this,” Sheroff exclaimed as he clambered back down.

Spontaneously, Mamel drew Sheroff to him and gave her a kiss.

“I kind of surprised her. But she was open to it,” he remembered.

Since then, Mamel, 87, and Sheroff, 74, have become a deeply committed couple. “Most nights, I’ll have dinner with Marg and many nights I stay with her overnight,” Mamel explained.

And yet, despite the romance, these North Carolina seniors live in separate houses and don’t plan to move in together or marry. Demographers call this type of relationship “living apart together” (LAT).

“It’s a new, emerging form of family, especially among older adults, that’s on the rise,” said Laura Funk, an associate professor of sociology at the University of Manitoba in Canada who’s written about living apart together.

Questions abound about these unconventional couplings. What effects will they have on older adults’ health and well-being? Will children from previous marriages accept them? What will happen if one partner becomes seriously ill and needs caregiving?

Researchers are beginning to focus on these concerns, said Susan Brown, chair of the sociology department and co-director of the National Center for Family and Marriage Research at Bowling Green State University in Ohio. “It’s really remarkable that older adults are in the vanguard of family change,” she said.

How many older adults are in LAT relationships? According to a 2005 survey by the National Social Life, Health, and Aging Project, 7 percent of individuals between 57 and 85 years old described themselves as living apart together. (Some experts contend the measure used in this survey was too broad, allowing couples who are dating to be included.)

Last month, at the annual meeting of the Population Association of America in Denver, Huijing Wu, a graduate student in sociology at Bowling Green State University, presented an analysis of nearly 7,700 Wisconsin adults age 50 and older surveyed in 2011. Married couples accounted for 71.5 percent of that group, single people accounted for 20.5 percent, and people who were “partnered but unmarried” accounted for 8 percent.

Of the partnered group, 39 percent were in LAT relationships, according to a more focused definition of this arrangement, compared with 31 percent who were dating (a less committed, shorter-term relationship) and 30 percent who were cohabiting.

Jacquelyn Benson, an assistant professor of human development and family science at the University of Missouri, is among a handful of researchers who’ve asked older adults about their experiences in LAT relationships. “Older adults really see this as a lifestyle choice, not a relationship of convenience,” she said.

Benson’s 2016 study of 25 older adults (from 60 to 88 years old) in LAT relationships found various motivations for these partnerships. Seniors wanted to have “intimate companionship” while maintaining their own homes, social circles, customary activities and finances, she discovered. Those who’d been divorced or in unhappy earlier marriages didn’t want to tie themselves down again and believed a degree of distance was preferable to day-to-day togetherness.

Also, several women who’d cared previously for sick parents or husbands wanted to avoid assuming caregiving responsibilities or the burden of running a household again.

“It’s a been-there-done-that attitude,” Brown explained. “I took care of my husband, I reared my children, and now it’s my time.”

Caregiving is a thorny issue, on multiple fronts. The only known study to look at caregiving in LAT relationships, out of the Netherlands, found that about half of partners planned to provide care, if needed — a sign of ambivalence. But when illness entered the picture, partners offered assistance nonetheless.

“People in LAT relationships forget there’s going to be this emotional entanglement and they won’t just be able to walk away,” Benson said.

Other complications can arise if adult children resent or fail to recognize their older parent’s outside-of-marriage relationship. “In some cases, when a partner wants to step in and have a say, they’ve been pushed out by family members,” Benson noted.

One older woman in her study learned that her partner had been placed in a nursing home by his family only when she couldn’t reach him at home anymore. “They didn’t include her in the conversation at all,” Benson said, “and she was pretty upset about it.”

Only a few studies have evaluated the quality of LAT relationships, which has implications for seniors’ well-being. One found that older adults in these relationships tend to be less happy and receive less support from partners than people who are married. Another, presented at last year’s Population Association of America meeting, found that the quality of LAT relationships isn’t as strong as it is for marriages.

“People in LAT relationships forget there’s going to be this emotional entanglement and they won’t just be able to walk away.”

That hasn’t been true for Luci Dannar, 90, who’s been involved with James Pastoret, 94, for almost seven years, after meeting him at a dance at a Columbia, Mo., senior center.

“The first feeling I had for Jim was sorrow because he seemed to be grieving from his wife’s death five months before,” said Dannar, whose husband and oldest daughter both passed away 19 years ago. “I thought maybe I could be helpful to this man because I’d been through those deaths.”

After getting to know Pastoret and realizing she liked him, Dannar laid down her terms. “I told him, I don’t ever want to get married and he said ‘I don’t either,’” she remembered. “And I said if you have a jealous bone in your body, don’t darken my door again. Because I lived 53 years with a jealous husband, and I never want to go through that again.”

Neither wanted to give up their apartments in a retirement community, about 300 steps from each other. “I like my independence,” said Pastoret, who taught in the school of natural resources at the University of Missouri for 33 years. “When I go home at night after supper with Lucy, I’m very happy to be by myself.”

“He comes over at 5 every evening and leaves here about 9, and then I have two hours by myself — my private time,” Dannar said. “We really like our space, our time alone, and we don’t need to be together 24 hours a day.”

Unlike other older LAT couples, they’ve talked about the future and toured assisted living centers together. “Someday, if he needs me to help him or I need him to help me, we will probably rent an apartment together, with our own bedrooms, and hire extra help,” Dannar said. “Our plan is to take care of each other until one of us is gone or we go into a nursing home.”

William Mamel is already making good on a similar promise to Margaret Sheroff, who had a mass removed from her gall bladder late last year and recently was hospitalized with complications from chemotherapy.

“With her in the hospital, I spend most of my days there,” said Mamel, who was a good friend of Sheroff’s with his wife of 37 years, Betty Ann, who passed away 2½ years ago. “Being caregivers for each other isn’t even a question.”

Their situation is complicated by Sheroff’s guardianship for her husband, John, who has advanced dementia and resides in a nursing home. “Marriage isn’t in the picture for us, but that doesn’t matter,” Sheroff said. “We’re taking one day at a time and enjoying being together.”

“Just to be able to have someone that you can wake up with in the morning and talk to, someone to have coffee with and see the smile on their face, is such a blessing,” she continued. “At this time of life, it’s really, really important to have someone in your life who’s there for you.”

KHN’s coverage of these topics is supported by John A. Hartford Foundation andThe SCAN Foundation.

This story was written by Judith Graham and contributed by Kaiser Health News, a national health policy news service that is an editorially independent part of the Henry J. Kaiser Family Foundation, a nonprofit, nonpartisan health policy research and communication organization not affiliated with Kaiser Permanente.