They were married for 20 years, raising a son and living the good life jetting between homes in New York and France.

It was all perfect, except for one thing: He had secretly divorced her just months after their wedding, in an apparent attempt to shield his assets.

Now Cristina Carta Villa, 59, is suing her 90-year-old “husband,” Gabriel Villa, to nullify the divorce she never knew about — and keep him from selling an apartment they shared.

The two met at a friend’s house, quickly tying the knot in a New York ceremony in 1994. She left her job teaching Italian literature at Boston College to be with the lawyer and travel agent more than 30 years her senior.

“He was absolutely charming, and despite our age difference, it was love at first sight,” says Cristina Carta Villa.

But all the while, Gabriel was apparently hedging his bets. Four months after the pair tied the knot, Gabriel Villa secretly arranged for a divorce in the Dominican Republic.

The wife says she never knew about, let alone consented to, a Dominican divorce, which was never registered in New York.

“It’s a fraud,” she tells The Post.

The two bought a one-bedroom condo on West 55th Street; had a son, Lorenzo; and divided their time among Manhattan, Massachusetts and France.

“It was and somehow it’s still a great love,” Cristina Villa says. “Gabriel is a very charismatic man, strong, intelligent and very charming. I think we could say I was a loving and caring wife and mother.”

When her husband was ill in the hospital, Cristina says, “I was always at his side.” He even made her his health-care proxy and gave her power of attorney.

But Gabriel allegedly told Dominican authorities life with his wife was “unbearable,” Cristina now alleges in court papers.

Even though the couple didn’t live in the Dominican Republic, Gabriel launched the legal dissolution there. He hired lawyers to represent each spouse and cited “incompatibility of temperaments” as the reason for the split, Cristina claims in a Manhattan Supreme Court lawsuit.

Cristina found out about it only in November when a tax bill arrived for their Manhattan home and her name wasn’t on it. She hired a lawyer to investigate, only to learn that Gabriel had tried to remove her name from the deed, using the Dominican Republic proceeding as proof she was not an owner, she charges.

The wife says in court papers she “has no recollection of [giving] any authorization to anyone to proceed with a divorce, or even thinking about divorce from the man she had just recently married.” If legal authority was given, she was either “surreptitiously impaired, drugged or misled” into giving it, claim court papers.

“I realize now that during all these years of joy and happiness, and of difficult moments we shared together, my husband lied to me and had the Dominican divorce on the back of his mind. It’s what is hurting me the most,” she says.

The divorce isn’t even legal in the Dominican Republic, Cristina argues, because neither spouse appeared in the court, and the split wasn’t published in a newspaper as required under Dominican law.

Cristina believes greed is behind the divorce duplicity.

Gabriel is “using an illegal and fraudulent divorce . . . to rob her,” Cristina charges.

She believes her husband wants to sell the apartment to his adult daughter, Marina Villa, who lives in Rome. One-bedroom condos in the Midtown building sell for roughly $1.4 million, records show.

Gabriel and Marina Villa did not respond to messages.