Updated

Frank Sinatra allegedly considered returning to his first wife, Nancy Sinatra Sr., during his final years.

The claim was made by Tony Oppedisano, who served as a member of the late star’s management team that also managed comedian and mutual friend Don Rickles. The award-winning producer recently wrote a memoir titled "Sinatra and Me: In the Wee Small Hours" about their decades-long friendship, which started when Oppedisano was just 21.

He told Fox News it was Nancy who encouraged him to share his story before her passing in 2018 at age 101.

"Nancy was probably the single longest friendship that he had in his life," said Oppedisano. "And there was a comfort there. But that didn’t change the fact that Frank was very much in love with Barbara, his last wife, obviously. Their marriage lasted 22 years longer than any other marriage in his story. And it was something that probably couldn’t really ever happened because too many people would have gotten hurt."

FRANK SINATRA WASN’T RONAN FARROW’S FATHER, PAL CLAIMS IN BOOK: ‘HE WOULD HAVE ACKNOWLEDGED HIM’

Nancy Sinatra Sr. was Frank Sinatra's childhood sweetheart. They were married from 1939 until 1951. (Getty Images)

"There was no way of figuring out how to put that relationship back together by the way of revisiting a marriage without what would have happened then between him and Barbara," Oppedisano continued about his pal. "So he was between a rock and a hard place. But they did remain very, very close."

Sinatra and Nancy first began dating as teenagers and married in 1939, just as the singer’s career was about to take off. Three years before marrying the former Nancy Barbato, he had landed a 15-minute radio show on local station WAAT.

During the marriage’s early years, the Sinatras lived in a modest apartment in Jersey City, where their two eldest children were born. For a time, Nancy was employed as a secretary while her husband worked as a singing waiter.

After Sinatra became a pop music sensation in the ‘40s, the couple moved to Los Angeles, where he would become a movie star and notorious womanizer. Nancy left Sinatra after his affair with actress Ava Gardner became public. Weeks after the pair’s divorce became final in 1951, Sinatra married Gardner. Nancy went on to raise their three children: Nancy, Frank Jr. and Tina.

RAT PACK'S JOEY BISHOP AND FRANK SINATRA NEVER RECONCILED FOR THIS REASON

Author Tony Oppedisano (Big City Broadway)

After the gossip over the divorce and the Gardner marriage died down, Nancy devoted herself to family and numerous celebrity friends, largely withdrawing from the spotlight. She not only outlived her ex-husband, who died in 1998, but also her son, who died in 2016.

"Nancy cared for Frank very, very deeply," said Oppedisano. "After a while, I actually felt comfortable enough asking her some sensitive questions and she didn’t balk. I asked, ‘When you first learned about Frank and Ava, why wouldn’t you give him a divorce initially?’ 

"She said, ‘Well, because that was just one aspect of his life. At the end of the day, he always came home to me. He was always a tremendous father. He was always there for the kids, no matter what. The only reason I did eventually decide to grant him a divorce was because back in those days, if you were a public figure, like he was, and fooling around with someone, and it was known that you were married and had children, it would really damage your career.’"

"Nancy said, ‘It was hurting him professionally,’" Oppedisano said. "'And so that’s why I gave him a divorce.’ Talk about love."

FRANK SINATRA BELIEVED MARILYN MONROE WAS MURDERED, FORMER MANAGER CLAIMS IN BOOK

Frank Sinatra and Nancy Sinatra Sr. shared three children: Nancy, Frank Jr. and Tina. (Getty Images)

Nancy remained friendly with Sinatra. It’s been said that over the years, he would put in requests for pasta and other Italian foods she was known to be an expert at preparing.

"There is no bitterness, only great respect and affection between Sinatra and his first wife," Gary Talese wrote in 1966. "And he has long been welcome in her home and has even been known to wander in at odd hours, stoke the fire, lie on the sofa and fall asleep."

Nancy never remarried. And for her, the decision was simple.

"I remember I asked her, ‘Why didn’t you ever remarry?’" said Oppedisano. "She said, ‘Well, for one thing, the children were small. I never wanted my kids to doubt who their father was. That was always number one for me. And [over the years] I thought about it. And I realized, once you’ve married Frank Sinatra, how the hell am I going to top that one?’"

CLICK HERE TO SIGN UP FOR THE ENTERTAINMENT NEWSLETTER

Nancy Sinatra Sr. never remarried. (Photo by Ron Galella/Ron Galella Collection via Getty Images)

Oppedisano believed that Nancy may have held on to hope that the couple would enjoy a Hollywood ending at some point in their lives.

"I think that was something she fantasized about, that maybe they would be able to figure out a way of getting back together," he claimed. "But they knew it would probably never happen."

But their close bond was undeniable, he insisted.

"They both had the same philosophy about a relationship, whether it was going to last or not," he explained. "If you enter into a marriage, it’s great. But if that marriage is not based on a very solid friendship first, then you're building houses with foundations made of sand. Sooner or later, it’s going to collapse. Nancy was always very supportive of Frank in his early years when he was trying to become somebody. She remained devoted as the mother of his children."

CLICK HERE FOR THE FOX NEWS APP

Shortly after his divorce from Nancy Sinatra Sr. (pictured here) Frank Sinatra married actress Ava Gardner. That union lasted from 1951 until 1957. (Getty Images)

Sinatra’s marriage to Gardner lasted from 1951 until 1957. He later married actress Mia Farrow and their union lasted from 1966 until 1968. The star said "I do" once more to Barbara Sinatra, a marriage that lasted from 1976 until his death at age 82.

Barbara, a former model who became a prominent children’s advocate and philanthropist, passed away in 2017 at age 90. Oppedisano said he was an honorary pallbearer at her funeral.

Barbara met Sinatra through her second husband, Zeppo Marx of the famous Marx Brothers comedy team. The couple had been close friends and neighbors with Sinatra until she left Marx for the singer in 1973.

Sinatra didn’t ask his fourth wife to marry him until she threatened to leave, she recalled in her 2011 memoir, "Lady Blue Eyes: My Life with Frank Sinatra." 

"The world loved Frank Sinatra, but at the end of the day, he was just a regular guy with a dream who cared a lot about people," chuckled Oppedisano.

The Associated Press contributed to this report.