03/25/2014 10:03 am ET Updated May 25, 2014

5 Naked Truths About Sex, Your Parents -- and Alzheimer's

Sexual urges can run hot and bothered long after an Alzheimer's diagnosis -- in ways that can often leave surprised targets simply bothered. Imagine your dad grabbing for your breasts or your mom trying to French kiss your husband. Or seeing your demure stepmother suddenly open her shirt at brunch to flash the waiter.

Stressed family caregivers swap plenty of stories about inappropriate sexual behavior by someone with Alzheimer's or another form of dementia. It doesn't happen with everyone. But when old images of loved ones bump (and grind) against new realities, it helps to remember these five truths:

1. Yes, it's okay to be freaked out by Alzheimer's sex behavior.

Just please don't show it.

Shock, embarrassment, or dismay are very common first reactions. Or all three. It felt startling enough when my own dad, who had dementia, confused me with his sister; I'm not sure what I'd have done if he'd mistaken me for my mom and our very G-rated relationship turned toward the X. All our lives, our parents' sexuality is a private thing we'd rather not think about. No wonder we feel emotional whiplash when dementia's loss of self-control rips off the sheets.

Shrieking and shaming are pointless, though, when someone has lost the cognitive ability to calibrate what's okay.

(Couples have their own, different issues to grapple with when Alzheimer's climbs into bed, which I've written about in this post. And in this article.)

2. Libido is libido, Alzheimer's or no Alzheimer's.

A psychiatrist friend recently told me about a patient who'd been mortified by his father who called a hooker every night from his nursing home. The impulse was still there, but by the time she arrived, he'd forgotten why he called her. "He pays her anyway," said the son. "We're going broke!"

Feeling sexual is normal at any age or health status. It's when sexual behaviors collide with poor impulse control, confusion, and an inability to read social situations that discomfort ensues. Boredom, loneliness, or the lack of a partner can amp up amorous feelings.

Probably not surprisingly, people who were hypersexual before they had dementia are often the same after.

3. Inappropriate sexual behavior is often a case of the nearest port in a storm.

Most experts advise against reading too much into these sexual come-ons. A father with Alzheimer's who hits on his daughter isn't revealing long-harbored incestuous feelings; his mind just confuses one person with another. When one man with Alzheimer's began propositioning his wife's best friend of 35 years, the friend was horrified, and worried it would be mistaken for proof of a past affair they'd never had. Fortunately the wife understood there was no long-burning secret crush. As is often the case, the friend, who visited often, was simply a convenient target.

Disinhibition about sex affects about one in four people to one in five with dementia. Men and women are thought to be equally affected, but there are more complaints about men.

4. You can often spot (and nip) a trigger.

One woman's dad developed the habit of undoing his pants as soon as he needed to use the bathroom -- but then he'd forget this and, as if on autopilot, start masturbating. Things improved when she encouraged a schedule of bathroom breaks (especially when the grandkids were around).

Bathing, being an intimate act, is another common trigger. A switch to a helper of the same gender solved the problem of randy grabs for one caregiver. Another monitored how much her mom drank; alcohol can lower the inhibitions of someone with dementia, just as in someone without it.

Sometimes what we read as sexual isn't, exactly. A restaurant "strip tease" might start because the room is simply too warm or the person is confused about where she is. When a startled onlooker stared at one caregiver's stepmom, who did this, she flashed her bra more brazenly -- with more than a little pride. "Apparently, she used to be widely admired for her hourglass figure," says the stepdaughter.

5. Pre-empt where you can.

Many caregivers find that it helps to simply show more nonsexual affection -- hugs, shoulder rubs, general attentiveness. Sometimes the sexual expression is borne out of a basic human desire for attention. For the woman prone to stripping, hard-to-undo blouses with back buttons helped.

And as is true for many stressful Alzheimer's behaviors, diversion can be your best friend. Calmly introduce a new line of conversation or activity, for example. Create a full household routine with varied things to do and people to interact with.

Don't overlook the creative solution. When a three-foot-tall Pink Panther doll was provided to a 68-year-old man with dementia in a facility, he turned his advances there and stopped trying to molest staff, according to a 2008 report in the American Journal of Geriatric Psychiatry. The long, soft proportions of a body pillow might comfort a widow or widower accustomed to a bed partner.