Inside Cher’s Agonizing Break-Up With Sonny: Diva, 78, Reveals How Kiss From Young Guitarist Ended It — and Tells How Split Nearly Drove Her to Suicide

Cher is bringing readers inside the exact moment her marriage to Sonny Bono officially ended.

In an excerpt from the upcoming Cher: The Memoir, Part One, which will be released on November 19, the pop icon, 78, wrote about how a sudden kiss with a young guitarist was the final straw in the demise of her dwindling romance with her former husband.

RadarOnline.com can reveal that Cher heard through a friend that a man named Bill, who joined the couple's band, had a "crush" on her. Although the Mermaids star originally brushed off the idea because of her union with Sonny, she began to entertain the idea.

"I found myself in a group in a booth with Bill, a tall 21-year-old with a Texas drawl, sitting next to me and putting his hand on my knee. To this day, I don't know how he was so bold," she penned in the passage obtained by Daily Mail. "Later, I joined Bill in the hotel lobby when he went to buy some cigarettes. There we ran straight into David Brenner, the stand-up comedian who opened our act. He almost passed out at the sight of me on my own in public with Bill. Me with a guy by myself? He might as well have seen Frankenstein with Dumbo."

After being seen by a close friend of her husband's, things between Cher and her new flame took a steamy turn. "Bill and I went outside to a big brick wall behind the hotel, leaning against it quietly side by side until he suddenly blurted, 'We all wonder how you can live this way.' Then he pulled me toward him and kissed me," she recalled.

"It felt like my head almost exploded off my shoulders. Bill was a great kisser, but more than that, Sonny didn't like to kiss. This kiss was what I'd imagined in sixth grade when I knew that kissing was in my future," the singer added.

However, the magic quickly dissipated when Cher got a call from Sonny who found out about her tryst with the musician. "'What the f--- do you think you're doing, Cher?" she recalled the late politician, who died 1998 in a skiing accident, yelling at her.

"You could have heard a pin drop. 'Have you lost your mind? Come back to the room,'" Sonny told her. "I had no idea who I even was at that moment, because I told him: 'Bill wants to understand more about his publishing rights, so I thought I'd bring him up to our suite.'"

"If I were Bill, I would have been thinking, 'This is a bad idea, that's my boss upstairs, I'm not going to go up to your room', but he came with me and when we walked into our suite Sonny was waiting in a chair, staring at us in complete silence," the Moonstruck actress wrote.

After Sonny shockingly allowed Cher to spend the evening with Bill, where she made it clear they did not get intimate that specific night, the following day, the power couple knew their romance was officially done. "Sonny came around my side of the bed, picked up my hand, and pulled my wedding ring off my finger. It took me a second to realize what he was doing, but I was too exhausted to care," the tome reads.

"Ever since we'd first started living together, he'd been secretly convinced I'd leave him one day, something he didn't properly tell me until years later, although he'd written it in a poem he gave me way back. There was a line, 'a butterfly to be loved by all but not by one,'" she noted.

Before they both agreed to divorce, Cher and Sonny's marriage got so bad she contemplated taking her own life. "Standing barefoot on the balcony of our suite at the Sahara hotel in Las Vegas, I stared down, dizzy with loneliness, as I saw how easy it would be to step over the edge and simply disappear," the brunette beauty said.