Ione Skye Reveals She Slept with John Cusack in Juicy New Memoir (Exclusive)

Actress Ione Skye, 51, is an open book in her debut memoir Say Everything. (Out March 4).

The delightfully juicy tome details everything from the Say Anything star’s bohemian childhood, her fraught relationship with her father, ‘Mellow Yellow’ singer Donovan and tons of famous friends like River Phoenix, Keanu Reeves, Sofia Coppola, Madonna and her first husband, Beastie Boy Adam Horovitz.

“I’m a little nervous,” Skye tells PEOPLE of name-checking so many celebs in the book. But she also says that at her age, she’s found peace with telling the truth about her life and career.

“I think as you get older, you feel freer just taking chances creatively and not worrying so much about everybody being happy,” she says. “Or worrying about looking like a fool.”

“I definitely don’t want to hurt anyone. But some people I named in the book have read it, and luckily everyone has loved it.”

One of those readers? Her Say Anything costar John Cusack. Skye had always maintained that while they had crushes on each other during filming, they never hooked up on set. In the book, she divulges that they eventually did sleep together, albeit years later.

“I had to get it out of my system,” she writes in the book, of getting together with him after her divorce from her first husband, Adam Horovitz.

She says she allowed Cusack to read a draft of her memoir, and afterward, he texted her: “You made the experience sound so meh! It wasn’t ‘meh’ for me,” he told her.

“I was like, I’m telling a story, and it was more about how all of our chemistry was in our working together and stimulating each other’s minds, not sleeping together!” Skye says, adding with a laugh, “I felt a little bad, but, oh well.”

Skye, who began acting at age 16, also reveals other crushes she had on costars, including her longtime friend River Phoenix, with whom she starred in 1988’s A Night in the Life of Jimmy Reardon.

“River ended up being a brother to me, but I remember at the time thinking, ‘Oh I’m in love with him!’ I couldn’t wait to do my kissing scene with him. He was just delicious.'”

She also goes into her tumultuous relationship with rocker Anthony Kiedis, whom she dated when she was 16 and he was 24 and struggling with a heroin addiction. Skye also had an abortion after getting pregnant by him in her late teens. “I’m not in touch with him,” she admits, admitting that she’s a little nervous over what he’ll think of the book.

Skye also opens up about meeting and falling for Horovitz when she was 20, and what it was like being part of the “It Couple” of the early ’90s.

The duo got married in 1992, but during their union, Skye discovered her bisexuality and entered into a series of affairs, including one with model Jenny Shimizu, the author reveals. They eventually divorced in 2000, and Horovitz later married Bikini Kill singer Kathleen Hanna.

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“I wrote to Adam,” Skye says, of letting him know he’d be in the book. “He’s private, but also such a big part of my story so he couldn’t not be in it.”

One person who she knows won’t have any issue with the book is her husband of 15 years, Aussie rocker Ben Lee. (The two share daughter Goldie, 15, and Skye is mom to daughter Kate, 24, with her ex David Netto.)

“My husband, yeah, he knew everything,” Skye says of Lee, 46. “I mean, he’s kind of amazing. I don’t think anything ruffled his feathers except that I spent so much time ruminating on a lot of the early chapters, and then by the time I got to the end and his chapters, I was sort of rushing through it. And he was like, wait a minute, wait a minute. I’ve been by your side this whole time and you can’t rush through my part!”

Jokes and first-time author jitters aside, Skye just hopes that people will have as much fun reading her story as she did writing it.

“It’s almost like motherhood, in that you know it’s going to be a huge experience, but you don’t know how big until you get there,” she says of the three-year undertaking.

“But it’s one of my favorite projects I’ve ever done. I thought it would be kind of just annoying and difficult, but I ended up loving it. And yes, I do care about what others will think. But I also have the feeling that everything will be okay.”

Say Everything is available now, wherever books are sold.