Story highlights CNN's Shanon Cook remembers men flirting with her while she was pregnant

Sex educators say the attraction is not uncommon

Experts say it might be because women find new confidence during pregnancy

Another theory: Men know pregnant women are able to reproduce

I recently saw video of an interview I'd done a couple years ago, when I was ginormously pregnant. Next to Annie Lennox, I was nine months along, with body parts bloated beyond recognition and heading in directions they normally don't.

My breasts were falling to the sides -- why had someone not told me to wear a more effective push-up bra? -- my face was all puffy. I swear, I counted one, two -- no, three -- chins below my overly smoky eye shadow.

And then there was the belly -- a massive dome of a thing, so immense that Lennox looked like a wee Scottish lass beside me.

"There was something behind his charming smile, his lingering and the urgent look in his eyes," Cook remembers.

Jessica-Simpson-on-the-cover-of-Elle, no. Sexy, I was not.

But then I remembered an odd event that occurred hours after that encounter with Lennox, long after the eye shadow was wiped off. I was in a grocery store checking out avocados when a man approached. He was probably in his early 40s, clean-shaven, dressed in a sharp gray suit.

"Congratulations!" he said, beaming. "How far along are you?"

"Oh, I'm due in three weeks," I replied.

"You must be excited," he said. I didn't tell him that excitement doesn't really register when it takes a forklift and three bodybuilders to raise you out of bed in the morning.

"Is it your first?"

"Mmm hmm."

Ordinarily an exchange like this would wrap up at that point, especially since I'd found the perfect avocado and was ready to continue shopping. However, my curious new friend refused to budge. He had more questions. Boy or girl? Feeling good?

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I wasn't sure whether to start lobbing bell peppers and radishes at the guy, or just accept the chatter as that kindness from strangers only pregnancy evokes. My instincts told me there was more to it and when pregnant, your instincts are pretty darn noisy. There was something behind his charming smile, his lingering and the urgent look in his eyes.

This dude thought I was hot.

But how could he? I mean, I looked like an upright hippopotamus. Was he merely homing in on the obviousness of my fertility? Did he have a thing for maternity jeans? How is it possible that when your pregnant self feels your stretched-out worst, you're able to attract random-dude-in-Tom-Ford in the fruit and veggie aisle?

But sex educator Logan Levkoff says during pregnancy, it's possible for women to be at their absolute best, and for others to see that, too.

"There is something about being pregnant that gives you this sense of confidence being in your own skin," she says. "The idea of having to exercise until you're blue in the face and be stick skinny and fit into the tiny little things, you kind of think 'This is not that time.' And there is something about owning that and owning your body ... and people pick up on that."

Levkoff, who wrote the book "How To Get Your Wife To Have Sex With You," also points out that a voracious appetite for food when eating for two translates to an appetite for other things -- life in general and, of course, sex.

It's no secret that the surge of pregnancy hormones can get a knocked up gal very worked up. I've heard husbands say that sex with their pregnant wives is the best they'd ever had.

But that's within a committed relationship. I was taken aback when one of my single guy friends once told me having sex with a pregnant woman was high up on his bucket list. What, like climbing Everest and going fly-fishing naked? What's that about?

I decided to ask my friend Marco Contini. He's a father of three, and Italian -- he tends to be very up-front about sexual matters. To my surprise, he admitted that he finds pregnant women attractive. And it all starts with "the glow."

"As banal as it may seem, it does have something to do with the light," he says. "Among other nonpregnant ladies, a pregnant woman does shine. Which, if you think about it, is technically absurd, since often enough the glow comes along with visible signs of fatigue and pimples."

And kankles. And stretch marks. And spatula-flinging outbursts of rage.

"Another more obvious aspect is the boobs," Marco said. "But that only applies to women one already knows well enough to notice the change."

Yeah, yeah. The boobs. Breasts get bigger during pregnancy, transforming even the smallest-chested woman into Sofia Vergara. But it was this next comment from Marco that really got me thinking: "A pregnant woman always brings out an odd mix of physical attraction and desire to be protective."

Protective. Even when the woman is not carrying his child? Could there be some kind of biological spell at work here?

Maybe, says neuropsychiatrist Dr. Louann Brizendine, author of "The Female Brain" and "The Male Brain. " Brizendine says pheromones given off by a pregnant woman are known to suppress the testosterone levels in her male partner and increase his production of the hormone prolactin. These changes might play a role in forming "daddy brain," a state that keeps the father rooted to the mother so he'll help care for her and the baby after the birth. Perhaps, Brizendine suggests, there was something "pheromonal" going on while I was in the grocery store that day. (She notes, though, there's no evidence that pheromones could work so quickly on humans in such a situation.)

Let's go back to the visuals for a minute, since after all, pregnancy is an astonishingly visual adventure. Brizendine says men are wired to scan for the telltale signs that a woman is fertile -- an hourglass figure, breasts and a flat abdomen signaling that she hasn't been impregnated by someone else. Why then are some men sexually attracted to women with a distinctly un-flat abdomen?

"When you're very pregnant there is this undeniable evidence you have had sex with a man," Brizendine says. "And that can be titillating. It's like wearing a billboard sign on your body: "I! Had! Sex!"

What else a pregnant belly might advertise: I'm! Safe!

"The male may feel maybe he can flirt with her in some way and have her not take it the wrong way," Brizendine says. "Or because she's already pregnant [he doesn't] have to worry about contraception. These things may not all be conscious in the male who's leering at you but they may be percolating in the back of his brain somewhere, that you're a safe target."

I know. Pregnant women reading this are cringing. It is a bit "Ewwww." Sex with your baby daddy, least of all a stranger, might be the last thing on your mind right now, especially if you've been constipated for eight days and have an overactive bladder.

So we can't forget, there's also the fetish angle. An abundance of pregnancy porn online proves there's a contingent of the population with a desire for pregnant women that goes beyond mere curiosity. (We should remind ourselves that fetishes exist for all kinds of things -- feet, ponytails, penguins; you name it). Brizendine says some of her patients do express an erotic interest in very pregnant females.

study published in The Journal of Sexual Medicine in 2011 suggests there's a link between sexual attraction to pregnancy and exposure to pregnancy and lactation in early childhood. The study found that a preference for pregnant or breastfeeding women was more common in individuals who had younger siblings; exposure to a pregnant mother between 18 months and 5 years might leave an imprint that manifests in adulthood.

Fascinating, yes. But let's cast aside studies and evolutionary biology and odd bucket lists for a second. We might really gain something useful from all this if we home in on Levkoff's idea that a woman has the ability to eschew her usual hang-ups about her body during pregnancy.

I remember that feeling. That let-it-all-hang-out easiness. In spite of the heft, I almost felt weightless when I was pregnant. We are so down on ourselves about our bodies so much of the time and pregnancy shields you from that nonsense (if you let it.) I ate peanut M&Ms by the truckload, loved my shapeliness, celebrated the life growing within me by smiling more and stood straighter than ever before -- though it might've been good posture that prevented me from toppling over.

"To be this kind of curvaceous superwoman (while pregnant) is something that we probably don't tap into enough," Levkoff says. "And if we could find a way to balance some of those feelings, that confidence in our everyday life, I think we'd all probably be a bit better off."

Toward the end of my interview with Annie Lennox in 2010, she looked directly at my mountainous belly and said in her delightful Scottish brogue: "I don't think I've ever been interviewed by anyone quite so pregnant!"

I was tickled pink that a pop veteran like Lennox would acknowledge my determination to keep working even though I was so far into my third trimester, when the pounds and discomfort come fast and furious. Clearly I didn't mind baring it all for CNN's cameras.

Part of me really misses that brazen broad with all her breadth. I'll think of her next time I'm pinching avocados in the supermarket, and perhaps pinch myself to stand a little straighter, smile a little more and wink at no one in particular.