When Dan Gasby, the husband of model and lifestyle guru B. Smith — who has Alzheimer’s disease — went public recently with his relationship with a new woman, it sparked fallout worthy of a tabloid tell-all: outrage, name-calling and an uncomfortable appearance on “The View.”

But the real reveal wasn’t Gasby’s new romance, or even the fact his new partner spends time at the home he lives in with his wife. It was a rarely discussed aspect of the world of dementia — the inner workings of marriages in the shadow of a disease that affects 1 in 10 Americans ages 65 and older, and about 5.7 million people in all age groups.

“No one is talking about this,” says Laura Gitlin, dean of the College of Nursing at Pennsylvania’s Drexel University, and author of “Better Living With Dementia: Implications for Individuals, Families, Communities and Society.” Even among the community of people who study, treat and advocate for Alzheimer’s patients, open discussion about how couples affected by Alzheimer’s choose to navigate intimate relationships outside the marriage has remained almost taboo. “I don’t think we’re even ready to have the discussion this suggests,” says Gitlin. “It’s truly a brave, new world.”

Yet, as our population ages — by 2050, Alzheimer’s dementia is projected to affect nearly 14 million Americans age 65 and older — we will increasingly need to answer the question Gasby’s romance raises: What are the boundaries of commitment and love when one partner can no longer remember the other or comprehend their shared history?

Marriage, in the best of times, is a complex compact, each union as individual as the humans who inhabit it. When dementia enters the equation, marriages change for both the patient and the caregiver who must “witness the change and decline of your loved one, the person transforming right in front of you,” says Gitlin. “People will adapt in different ways. Some people will feel very comfortable about the person they’re caring for becoming fond of someone else or the other way around. It’s just people surviving. There’s no road map.”

In 2007, Supreme Court Justice Sandra Day O’Connor, who had retired from the high court a year prior, made news when her adult son gave an interview that detailed his father’s move to a care facility for Alzheimer’s and his subsequent romantic attachment to another woman. He also explained that his mother was happy with the arrangement and would visit with her husband while he sat holding hands in a porch swing with his “girlfriend.”

The case illuminated a scenario that is familiar within the Alzheimer’s community. “It’s quite common that the person who has Alzheimer’s, who is maybe in a care facility, might forget that they’re married and develop a romantic friendship with someone,” says Melissa Tucker, the director of helpline and support services at the Illinois chapter of the Alzheimer’s Association.

Also not unheard of: spouses who divorce as Alzheimer’s encroaches, and even ex-spouses who move back in to become caretakers. “It’s a very emotional issue,” says Tucker. “And there’s no one right answer for everybody.”

The Gasby scenario, in which a healthy spouse seeks a new companion and is open about the relationship, even coexisting in the same space with both partners, is perhaps the most challenging to understand, simply because it requires nuance. There are no clear-cut heroes or villains. Gasby is unapologetic and open about his new relationship, posting about it on social media with the hashtag #whylie. Smith appears to be happy and lovingly cared for by a family who has chosen to keep her at home. Her adult stepdaughter is supportive of her father’s new relationship and also helps care for Smith.

Struggling to find an answer that fits your family, experts say, can be challenging in the shifting landscape of dementia. The solution, they say, might be to begin conversations about plans and preferences for the future as soon as possible after receiving a dementia diagnosis. And, if the family is comfortable, those discussions can include future relationship boundaries — think of it as a living will for a marriage. “People have different boundaries,” says Gitlin, “and part of being in any relationship is talking about that and being open about that, while you still can.”

When considering the ways in which relationships might change, Gitlin says, the most important clue comes from the past. “Understanding what the previous relationship was like is important here. What did the couple practice before, what are their religious beliefs, what is their moral compass? All of these things are going to affect people’s choices, both in wellness and under these circumstances. So there is not going to be one size fits all and what’s right and what’s wrong.”

It’s also important to plan with both the patient and the caregiver’s needs in mind, particularly since an Alzheimer’s decline can last anywhere from four to 20-plus years, potentially leaving a caregiver with decades of hardship to weather.

“Self-care for a caregiver is so important,” says Tucker. “If you are caring for a person with dementia, it is really one of the most stressful things you can ever experience, and it has real health consequences for the caregiver. Chronic disease goes up; depression and anxiety goes up; it’s really common for the caregiver to pass away before the person that they’re caring for.”

Gitlin hopes that, one day, family discussions of care for the caregiver can include the need for intimate companionship. “Sexual relationships are an issue that families want to talk about. And they’re not given any kind of support for that. The spouse who’s the caregiver, their intimate life is never discussed.”

If the family is able to address these issues, both Gitlin and Tucker stress that the key is to move forward without judgment.

“My only question,” says Gitlin, “would be: Is this relationship healthy for the spouse with dementia, and is it helpful? I would evaluate from a place of no judgment. Is this helpful for the patient, and for the spouse, who is the hidden patient?”

Families who choose to go public with their private choices, like Gasby’s, challenge those judgments and offer an opportunity for the rest of us, says Tucker. “Any time anybody comes forward and says anything about dementia, it’s really brave, because there is still so much stigma. This story is kind of an opportunity for us to be able to bring these things out into the open, so that maybe people who are having these thoughts or dealing with this can know they are not alone. It reminds me of how important it is to be sensitive and compassionate toward people.”