Priscilla Presley has shed light on her tumultuous relationship with Elvis in her new book and claimed he wanted her karate instructor killed after learning of their affair.

READ MORE: Sofia Coppola on baring Elvis’ ugly side in ‘Priscilla’: “I never wanted him to be a villain”

In her upcoming memoir, Softly, As I Leave You: Life After Elvis, she shared that she had an affair with her karate instructor, Mike Stone, during her marriage to Elvis. In a portion of the book obtained by Fox News Digital, Priscilla wrote of the irony of the affair, given she’d started taking karate lessons to impress her husband after learning about his own infidelity.

She discovered this after finding their mailbox “stuffed full of letters from girls”, and wrote: “I finally held written proof of what I’d always feared. I was deeply hurt, but I was also furious. I called Elvis and demanded an explanation. When that tactic failed, he resorted to saying the girls were all lying.

“This time, though, turning the tables didn’t work. If Elvis was having affairs that were none of my business, then it was none of his business what I was doing. The close friendship that Mike and I had developed turned into an affair.”

On Monday (September 22), she reflected on the mutual cheating in an interview with Today, and said there were “too many of us” in the marriage.

“They would go and meet Elvis at the house on weekends when he went, and it was another life. Now, he would come home great and wonderful. He was still a good husband, but it was just too many of us,” she said.

Priscilla claimed her affair with Stone infuriated Elvis to such a degree that he contemplated hiring an assassin to kill him.

“Elvis found the thought of me with another man unbearable. In the weeks after my departure, he told the guys that Mike had to die. He even asked Joe [Esposito] to find a hit man,” she revealed, referring to Elvis’ longtime road manager, who she added was also famously known as a member of the “Memphis Mafia”.

“Joe warned me to be careful. When I offered to bring Lisa [Marie Presley] to Vegas for one of Elvis’s shows, Joe advised against it. Seeing me might set Elvis off. Over time, and with a lot of persuasion from his father and the guys, Elvis gradually calmed down and gave up the idea of killing Mike, thank God,” she wrote.

Elsewhere, in her book, Priscilla claimed that when Elvis learned of the affair, he’d “forcefully” had sex with her, but made it clear that it wasn’t the reason she decided to file for divorce in 1972.

“I didn’t leave because of Mike Stone. And I didn’t leave because Elvis had forced himself on me when he found out about Mike. He had not. Elvis had felt emasculated. He’d needed to prove to himself and to me that he could make love ‘like a real man,’ the way he imagined a karate master doing it.”

“Elvis made love to me forcefully, not forcibly. His usual tenderness and consideration for me were missing. It was emotionally hurtful, and it left me with an unhappy memory of my last experience of sexual intimacy with Elvis. But it was not the reason I left,” she wrote.

Other recent revelations from her book include her strong disapproval of Lisa Marie Presley‘s relationship with Michael Jackson. In a newly shared excerpt, she said their brief marriage in the ’90s “appalled” her.