"First thing next morning, Jackie called to tell me how divine Alec was," wrote Simon in her new book, "Touched by the Sun: My Friendship with Jackie."
Jackie Kennedy Onassis had her share of nights on the town with highly publicized figures as she was married to an American President, and later a Greek shipping magnate billionaire.
But one of her illustrious evenings out was little known until now -- a "magical" date with a hunky Hollywood actor on the rise.
Per the DailyMail, Carly Simon wrote in her new book "Touched by the Sun: My Friendship with Jackie" about the time she and her then-husband James Hart asked Alec Baldwin to accompany the former first lady to a Broadway show in 1991.
The event, however, didn't appear to be romantic in nature as Onassis was in a relationship with Maurice Templesman -- he was out of town at the time and could not attend the show -- while Baldwin was dating Kim Basinger, whom he'd marry in 1993.
Baldwin was actually the third choice to be her escort after documentarian Ken Burns and media executive Joe Armstrong were unavailable.
But still, the invitation shocked the "Working Girl" star, according to Simon. "Jackie Kennedy wants to go on a date with me?" she said Baldwin responded. "Are you kidding?"
And Onassis was delighted in the fact that Simon suggested they go incognito, according to the book. "What about wigs? I can be Jean Harlow!" Simon recalled Onassis saying.
Simon -- who befriended Onassis after meeting her in Martha's Vineyard in 1983 -- said the fashion icon had a ball, even though the wigs were only used at the dinner party before the show.
"First thing next morning, Jackie called to tell me what a magical evening it was, how divine Alec was, and how important she felt it was to think and act and cavort like a child now and again," wrote Simon.
Meanwhile, Baldwin spoke of the encounter during an interview with Howard Stern back in 2017.
According to Baldwin, he was unaware of the set-up when he arrived for the dinner party at Simon's house.
"And I get there early and I'm sitting there and the mystery guest walks in and it's Jackie Kennedy," Alec told Howard. "And I think I literally, like, urinated in my pants -- I freaked out."
As to whether Baldwin would have pursued a romantic relationship with Onassis if she was interested, the actor said at the time, "If I was single and I was on my own, would I have had a fling with Jackie Kennedy? It's hard to say. I don't know. Maybe."