Priscilla Presley dated many famous men after divorcing Elvis, but she kept her relationship with Robert Kardashian to herself.

In her new memoir “Softly, As I Leave You: Life After Elvis” (Grand Central Publishing, 320 pp., on sale Tuesday, Sept. 23), she recalls leaping out of bed with Kardashian, who was sound asleep, to take a call from the King of Rock ‘n’ Roll at 2 in the morning.

Elvis would “have gone ballistic, maybe literally, if he’d known Robert was in my bedroom," she writes in an early copy of the book provided to USA TODAY. “Elvis always carried a loaded gun, sometimes more than one.”

It never occurred to him that Priscilla might have been asleep. And “it had certainly never occurred to him that I might be with another man.” She recalls Elvis brimming with enthusiasm as he described a great show that night (“Damn, I was knocking ‘em out!”).

After their chat, she slipped back under the covers, and neither man was none the wiser. "He never knew Elvis had called. And Elvis never knew about Robert."

She clarifies elsewhere in the book, though, “He never called me when I was making love to someone!”

Priscilla, now 80, met Robert through Joan Esposito − ex-wife of Elvis’ road manager, “Memphis Mafia” member Joe Esposito − who had started dating Robert’s brother, Tom. (They went on to marry.)

Though Robert wanted to marry Priscilla, she knew within a few months that he wasn’t her future: “I wasn’t ready to marry again.”

“Robert was a sweet man, and I liked him,” she adds. But “Robert had a demanding job as an attorney, working long hours five days a week. By the time the weekend rolled around, all he wanted was a quiet night at home with popcorn and a good movie. It was fine at first, but I gradually grew restless.”

They remained friends, however, and Kim Kardashian called Priscilla from the hospital in 2003, when Robert was dying with esophageal cancer, so they could speak for a final time.

“Robert and I had one last conversation before he died,” she writes. “He was the kindest of men, and I remember him with great affection.”

After their split, Kardashian famously went on to marry Kris Jenner in 1978 and have four kids: Kourtney, Kim, Khloé and Rob. Kris later married Caitlyn Jenner − who had previously been married to Elvis’ post-Priscilla girlfriend Linda Thompson − and they had two children: Kendall and Kylie.

This article originally appeared on USA TODAY: Elvis 'never knew' Priscilla Presley was in bed with Robert Kardashian when he called

Reporting by Kim Willis, USA TODAY / USA TODAY

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