It’s been 40 years since Joey “Crazy Joe” Gallo was gunned down in Little Italy’s Umberto’s Clam House, but the mobster’s bride of only three weeks remembers the notorious gangland slaying as if it were yesterday.

“It was very dramatic,’’ recalled Sina Essary, whose daughter Lisa, then 10, was also there when the assassins’ bullets rang out.

“This was the first time in history that the Mafia had shot and killed someone in front of his sister, wife and child,” she said.

Essary, now 70, can’t forget the chaos that erupted as Gallo’s party sat at a table in the early hours of April 7, 1972, and prepared to dig into second helpings of scungilli, shrimp and pasta when four assassins barged in and fired as many as two dozen gunshots.

“I have PTSD, although we didn’t call it that back then,’’ she said.“Even now, whenever I hear a car engine misfire, I jump.’’

Essary spoke to The Post from her farm, in a Nashville suburb, where she rescues thoroughbred horses and is writing her memoirs.

She and Gallo were an unlikely couple.

The charismatic gangster was targeted for death by the Colombo crime family because less than a year earlier, family boss Joe Colombo had been shot and permanently incapacitated — and Gallo was widely considered the wiseguy who set up the shooting.

The clown prince of the Mafia — who used to keep a mountain lion in his Brooklyn social club — was reputed to have been one of the shooters in the 1957 barber-chair slaying of boss Albert Anastasia.

He had spent a decade in prison on an attempted extortion conviction where he read French authors including Camus and Sartre.

Essary had planned to become a nun, but instead married, had a child and got divorced.

She moved into an apartment in the same 12th Street building where Gallo lived.

“To be honest, when I met him, I felt sorry for him,’’ Essary said. “He was all skin and bones.’’

Gallo’s Brooklyn tough-guy persona and intellectual patina proved hard to resist.

“He was very romantic. He would come home with flowers and gifts. I wasn’t used to that,” Essary explained.

Several days before the slaying, Gallo lost his temper with her for the first time when she unwittingly accepted delivery of a package at their apartment — a gift he thought might be a bomb.

On his final night, Gallo and his new bride enjoyed a champagne-filled evening celebrating his 43rd birthday at the Copacabana nightclub with the likes of comedian David Steinberg and actor Jerry Orbach, who played a character based on Gallo in the film “The Gang That Couldn’t Shoot Straight.”

The couple, along with Lisa, Gallo’s sister Carmella Fiorello, bodyguard Peter “Pete The Greek” Diapoulis, and his date, Edith Russo, later headed to Umberto’s on Mulberry Street.

Inside Umberto’s, a Colombo loyalist, Joseph Luparelli, spotted Gallo and limped off on his bum knee to tip off his pals.

Soon after, four assassins burst in and started firing at Gallo, who along with Diapoulis was seated with his back to the door. Their table turned over — and Essary used it as a barricade to protect her daughter as Gallo tried to escape the fusillade.

“I had a fur coat on her and I covered her with it completely and told her to just play dead,’’ Essary recalled.

Gallo, mortally wounded, staggered out to the street not far from his Cadillac, where he collapsed on his back in a puddle of his own blood. He died cursing the assassins, according to press reports.

No one was ever charged with Gallo’s murder.

Essary went on to marry and divorce both a gynecologist and a Wall Street financier. Her daughter is now a successful Hollywood casting director.

Thanks Stubbs. Never knew he had a wife, or that he was killed in front of her.