Shirley Jones is best known for playing wholesome characters.

The actress and singer stole America's heart in the classic musicals "Oklahoma!" and "The Music Man," and played one of the most beloved mothers in television history in the iconic 1970s sitcom "The Partridge Family."

But the Academy Award-winning actress is raising eyebrows with the revelations she makes in her autobiography, "Shirley Jones: A Memoir."

In the book, Jones looks back at her career, sharing her impressions of her many famous co-stars, including Burt Lancaster, Marlon Brando and Frank Sinatra.

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In an interview with "Good Morning America" correspondent Linsey Davis, she named Burt Lancaster as, probably, her favorite co-star, and said he was the best kisser of them all.

The memoir also delves into her affair with, and subsequent marriage to, actor Jack Cassidy, and also dishing on his sexual exploits.

"Well Jack was … he did it with men and women," said Jones, 79. "I mean he was, you know, he had an affair with Cole Porter and he told me about all this, by the way. I was very aware of all this. But he loved women!"

Jones revealed she and her husband once had a threesome with another woman, according to the Associated Press.

She married Cassidy in 1956 and they had three sons. Her "Partridge Family" co-star, David Cassidy, was Cassidy's son and her stepson.

The couple divorced in 1974, and Jones reportedly declined an offer to reconcile.

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Asked what was most difficult for her to share in the book, Jones replied, "My husband … I mean, he was my knight in shining armor, he was the love of my life. I was the breadwinner in the family and it was very difficult for him."

Jack Cassidy died in 1976, and the following year Jones married TV comedian and producer Marty Ingels.

"Had Jack not died - he was 49 years old when he died in a fire - I don't know if I would've married Marty," Jones told "GMA." "I don't know. I don't think I would've ever gone back to Jack, but I fell in love with Marty as I went along."

Jones has had a show business career spanning six decades, but it wasn't what she intended for herself.

She had dreams of becoming a veterinarian, and in the book she acknowledged that she sometimes wished she had followed that dream.

"I'm a nut about animals," she told Davis. "I wanted to do that, but I was given a gift."