“You have to do something pretty spectacular to stand out in Vegas,” a woman said to me at the MGM Grand pool in Las Vegas last weekend.

I assumed she was referring to me and my three friends, who were providing complimentary entertainment by donning inflatable sumo wrestler-sized ballerina costumes and prancing around poolside, a routine that was greeted with thunderous applause by a pool full of twentysomethings half a dozen daiquiris into the day under the Vegas sun.

As big of a hit as our act was, it was the sage wisdom of the woman at the pool that stuck with me later that evening …

My husband and I had dinner with two of my girlfriends — and fellow ballerinas — at Emeril’s at the MGM, a lovely seafood restaurant separated from the hustle and bustle of the complex by a glass wall, making for some great people-watching while enjoying a bowl of clam chowder.

Fortunately we had finished dinner when my husband spied a wardrobe malfunction of spectacular proportions on the other side of the glass. “What is that?” he asked, pointing out the window.

My girlfriends and I, along with our fellow patrons at the tables on either side of us, all turned to look. There, in the middle of the MGM Grand, stood a young lady wearing really cute shoes and a hip-length tank top.

Unfortunately no one noticed this, because she was not wearing pants. Not even the under kind.

As the bottom two-thirds of this woman’s bare tushie took in the world behind her, our dining section was abuzz with speculation.

“Is that a dress?” “Is that her (rump)?” “Isn’t it cold?”

Just then the girl — still standing with her back to us — reached way up the bottom of her shirt and retrieved the right half of a pair of black bloomers, which had apparently been held hostage by a superwedgie, and secured it over her right cheek.

“She IS wearing underwear!” we all cheered, marveling at how she had managed to hide that fact so well.

We watched a few more moments as the girl, perhaps sensing the imbalance, repeated the move on her left side and walked away.

Assuming she had fled the state, never to show her face — or anything else — in the desert again, our table resumed discussion about which Vegas entertainer should be voted out of North America. (Carrot Top.)

Suddenly the girl appeared again, this time with pants. It seemed her friends had staged an intervention I can only imagine went something like this:

Girl, smoothing her hair, “Does this outfit make my (rump) look big?”

Friend No. 1, looking down, “Um, your (rump) is totally showing.”

Girl, “What?”

Friend No. 2, texting, “Yeah, like for the last hour.”

Girl, “OMG! What should I do?”

Friend No. 1, handing Girl some pants, “It’s OK. At least you don’t look like those sumo ballerinas from the pool.”