First ladies don’t kiss and tell.

A racy “New York” magazine cover showing Melania Trump smooching a Big Apple firefighter in the wake of 9/11 has been unearthed nearly two decades later.

At the time of the photo shoot in 2002 — meant to be reminiscent of the iconic V-J Day smooch between a sailor and a nurse in 1945 — Trump was a little-known model named Melania Knauss who had been hired to pose on the cover of the publication’s Valentine’s Day “Singles” issue, according to New York.

Knauss — who at the time was dating Donald Trump, then known as a Big Apple property developer — was selected to star on the cover paying homage to New York’s first responders, who had become “rock stars” in the wake of the devastating 9/11 attacks months earlier.

“Recently, the journalist Matt Haber learned (via this Flickr post) something that we at New York had forgotten: The female model we’d hired was a pretty young Slovenian named Melania Knauss, who had been dating a New York real-estate developer on and off for several years, and married him a couple of years after that,” the new New York report describes.

“We did not, at the time, expect to be working with the future First Lady of the United States. But we were.”

Engine 7, Ladder 1 smoke-eater Daniel T. Keane — who also moonlighted as a part-time model — recalled how he and Knauss re-created Alfred Eisenstaedt’s famous end-of-WWII photograph.

They held the pose “a couple hundred times” — Knauss each time grabbing him and planting a big kiss on him, said Keane, now an FDNY battalion chief.

“The person who was doing my hair and makeup, they said, ‘Do you know who that is?'” he recalled.

“I don’t know any models, I really wasn’t into the scene. And they said, ‘That’s Melania Knauss … That’s Donald Trump’s girlfriend.’ And I said, ‘Oh, okay.'”

Just three years later, Knauss would appear on the cover of “New York” as Mrs. Donald Trump, and this time she was the star.