Women apparently aren’t allowed to sit at the bar alone anymore at high-end haunt Nello — because they could be mistaken for hookers.

That was what one horrified creative exec was told when she went to the Upper East Side eatery solo, only to be banned from the bar. And she’s written about the awful experience in an essay, “The Night I Was Mistaken for a Call Girl.

Clementine Crawford, of the renowned branding firm Finch & Partners, said she’s been a regular at Nello — the Madison Avenue restaurant famed for its $275 white truffle pasta dishes — for the last few years as she splits her time working between Manhattan and London.

But recently arriving at the eatery, “I perched at my favorite seat at the bar” when a waiter “advised — with evident embarrassment — that I was no longer permitted to eat at my usual spot and that I must now sit down at a table,” she recalled.

A few days later, the same thing happened: Crawford said she was told, “Nobody was able to eat at the bar. Company policy.” But while she was relegated to a table, she noticed a male patron at the bar being ceremoniously served a full pasta dinner, complete with “a limoncello” to cap it off.

“Why, I wondered, was I suddenly being treated so frostily? After further interrogation, it transpired that the owner had ordered a crackdown on hookers: the free-range escorts who roamed the Upper East Side, hunting prey in his establishment,” Crawford wrote in her essay for the website Drugstore Culture.

She added, “But hang on: Did this mean they thought that I was an escort? Or could be mistaken for one? At first, I was incensed. Not because I am judgmental about the world’s oldest profession, but because this treatment struck me as outright discrimination. They had classified me, marginalized me, relegated me to the corner by the loos simply because I was an unaccompanied woman.”

That’s when “I asked to speak with the owner to try and rectify the situation.” She explained that she “traveled for work and reminded him that I was a regular at his restaurant . . . That it was a brave thing to do, to eat out on one’s own. And this was their response?

“He told me that he could run his business as he pleased and that I was no longer welcome to eat at the bar, only at a table.”

She went on, “Things escalated quickly into an explosive argument. I told him what I thought of him in no uncertain terms and departed into the night with a heavy heart.”

In her piece, Crawford does not mention the restaurant by name, but confirmed to The Post that it was Nello.

In the end, she said of the “sexism that still silently seethes” in the #MeToo era, “It’s easy to focus on the front-page carnage. But it’s the demoralizing experiences of the everyday that really count.” And, “We are still fighting for a seat at the table (or bar).”

Nello did not respond to requests for comment.