“That thigh gap, though.”

Gross. I’ve seen those words countless times – comments and captions paired with an image of an itty-bitty girl’s waist in a teeny-weeny bikini, yellow polka dots or not, with this gaping space between her thighs.

“That thigh gap, though.”

Who decided that a gap between a woman’s thighs is desirable and necessary? Was it some guy behind a computer screen? A girl starving herself before bikini season? Either way, they’re both wrong.

For those that have lived under a social media rock for the past few years, a thigh gap is the so-called space between a woman’s thighs when she stands upright with knees touching. In other words, a mystical wonder that exists for only about 1 percent of women.

The phenomena got its start about two years ago following the 2012 Victoria’s Secret Fashion Show, which — as always — featured bony models and thigh gaps for days. One of the models, Cara Delevingne, inspired the start of a new parody/fan Twitter account celebrating Delevingne’s model-esque features. It’s called “Cara’s Thigh Gap.”

Social media sites only give fuel to the flames. Girls on Twitter use the hashtag “#thinspo” or “#thinspiration” on images of girls with thigh gaps in hopes to motivate others to be thin.

Blogs on Tumblr are devoted to the thigh gap. One is named “Thigh Gap Please.” One of its posts shows a photo of a girl — lower half only — with the words “If you want it so bad, stop eating.” Another says “Because thigh gaps are worth it.”

The fact that these photos don’t include a girl’s face is telling, I think. It’s as if the thigh gap is her identity.

Blogger Camille Hugh authored the book “The Thigh Gap Hack: The Shortcut to Slimmer, Feminine Thighs Every Woman Secretly Desires” last year.  It includes “hacks” on how to improve metabolism, lose body fat and motivate someone to exercise, in order to attain a thigh gap.

Hugh’s website, thighgaphack.com says that “technically, any woman can get a thigh gap if they lower their body fat and get skinny enough.”

Here’s the thing with the thigh gap: it doesn’t exist for the majority of women. Much of our body types are determined by genetics, and even if we did exercise ourselves sick, it still is not possible.

Angela Guarda, an associate professor of psychiatry at the Johns Hopkins School of Medicine and director of the Johns Hopkins Eating Disorders Program, explains in a Washington Post article that even lean athletes cannot achieve the thigh gap.

“Whether a woman’s inner thighs touch depends on bone structure, shape of the pelvic girdle and how far apart the hipbones are, in addition to weight,” the article states.

Because the thigh gap is nearly unattainable, women and young girls are resorting to unhealthy eating and exercising habits. It’s a futile attempt.

There’s nothing wrong with exercising to get results, but idolizing an impossible feat is harming our sisters and daughters. There’s a difference between searching for motivation — which is nowadays labeled “fitspiration” — and searching for false hope.

Instead of commenting on a girl’s photo with “That thigh gap, though,” try “That smile, though.” Those freckles, that personality, that imagination.

At least those things actually exist.