Priscilla Presley has revealed Robert Kardashian once wanted to marry her.

The pair were a couple in 1975, two years after her divorce from Elvis Presley.

In her new memoir, Softly, As I Leave You: Life After Elvis, 80-year-old Priscilla explained how Robert - who went on to marry Kris Jenner and father Kourtney, Kim, Khloé and Robert Kardashian - wanted to put a ring on her finger.

"Robert was a sweet man, and I liked him," she recalled. "Robert wanted to get married, but I knew it wouldn't work. I wasn't ready to marry again."

Priscilla also detailed how her crooner ex-husband once phoned her in the middle of the night when she was in bed with her new boyfriend.

"It hadn't crossed (Elvis') mind that I might have been asleep. It had certainly never occurred to him that I might be with another man," she explained. "Despite our divorce, he still couldn't wrap his head around my being with someone else."

She added she had been fearful of Elvis' reaction had he found out his ex-wife was sleeping with someone else.

"He'd have gone ballistic, maybe literally, if he'd known Robert was in my bedroom," she wrote. "Elvis always carried a loaded gun, sometimes more than one."