Matthew Perry is opening up about the crush he had on Valerie Bertinelli while the two were on the same show in the 1990s.

In Perry's upcoming memoir "Friends, Lovers, and the Big Terrible Thing," the actor detailed how the two ended up making out.

"I fell madly in love with Valerie Bertinelli, who was clearly in a troubled marriage," Perry wrote in his book, according to Page Six. "My crush was crushing; not only was she way out of my league, but she was also married to one of the most famous rock stars on the planet, Eddie Van Halen."

"It is important to point out here that my feelings for Valerie were real," he continued. "I was completely captivated — I mean, I was obsessed with her and harbored elaborate fantasies about her leaving Eddie Van Halen and living out the rest of her days with me."

Perry played Bertinelli's brother in the 1990 TV series "Sydney." The "Friends" star wrote in his book that he realized Bertinelli also had feelings for him when he was over at her and Van Halen's house one night.

"I was over at Valerie and Eddie's house, just hanging out and gazing at Valerie, trying to make her laugh. When you made her laugh, you felt ten feet tall," Perry wrote.

"As the night progressed, it was clear that Eddie had enjoyed the fruits of the vine a little too hard, one more time, and eventually he just passed out, not ten feet away from us, but still, this was my chance!"

he wrote. "If you think I didn't actually have a chance in hell you'd be wrong, dear reader — Valerie and I had a long, elaborate make-out session. It was happening — maybe she felt the same way I did."

"I told her I had thought about doing that for a long time, and she had said it right back to me," Perry wrote.

A representative for Bertinelli didn't immediately respond to Insider's request for comment.

But it turned out to be just a one-night thing. Perry wrote that Bertinelli acted like nothing had happened once they were back at work. "Sydney" was canceled shortly thereafter so Perry's dreams of having a relationship with his costar quickly faded.

"Inside I was devastated," he wrote.

"I have spent my life being attracted to unavailable women," he wrote. "It doesn't take a psychology degree to figure out that this had something to do with my relationship with my mother."

In the memoir, Perry also opens up about his alcohol and drug addiction.

"I would wake up and have to get 55 Vicodin that day, and figure out how to do it. When you're a drug addict, it's all math. I go to this place, and I need to take three. And then I go to this place, and I'm going to take five because I'm going to be there longer," Perry told The New York Times ahead of the release of the book. "It's exhausting but you have to do it or you get very, very sick. I wasn't doing it to feel high or to feel good. I certainly wasn't a partyer; I just wanted to sit on my couch, take five Vicodin and watch a movie. That was heaven for me. It no longer is."

Perry revealed in an interview with ABC's Diane Sawyer that, out of his "Friends" costars, it was Jennifer Aniston who would seek him out during his dark times with addiction.

"She was the one who reached out the most," Perry said. "I'm really grateful to her for that."