Kirstie Alley Tells All: Secret Romance With Patrick Swayze, Calls John Travolta 'Greatest Love'

ABC News' Vanessa Weber reports:

From "Dancing With the Stars" to her famously fluctuating weight, Kirstie Alley is a woman who loves to reinvent herself and isn't afraid to tell all. Her latest disclosure: a secret romance with Patrick Swayze.

The co-stars fell in love working on the movie "North and South," Alley said, and Swayze wanted Alley to get a divorce from her husband and marry him, but Alley wouldn't do it.

"I probably was more willing to break up my marriage, and I wasn't willing to break up his marriage," Alley told ABC News' Barbara Walters, in an interview about her new book, "The Art of Men," which details her ups and downs in life and in love.

Alley's acting career took off, and her love of Hollywood men did not end with Swayze. After a wildly successful run on "Cheers," Alley signed on to do a film with John Travolta about a talking baby: 1989's "Look Who's Talking" and love bloomed.

Alley described Travolta, who shares her commitment to Scientology, as "the greatest love of my life," and said she fought off the impulse to "run off and marry" him.

"Believe me, it took everything that I had inside, outside, whatever, to not run off and marry John and be with John for the rest of my life," she said.

Why didn't she?

"Because I feel like when you marry someone, you're supposed to work hard at it and you're supposed to make it work," she said.

Alley and Travolta made two successful sequels and became lifelong friends. The actress dashed the rumors that Travolta is gay.

"I know John. With all my heart and soul, he's not gay," she told Walters. "I think it's some weird way, in Hollywood, if someone gets big enough and famous enough, and they're not out doing drugs and they're not womanizing, what do you say about them?"

In spite of her love affairs - which Alley says never went farther than kissing - she stayed with husband Parker Stevenson, the former teen heartthrob of "The Hardy Boys" series, for 14 years. They divorced in 1997.

Alley's latest flirtation plays out before millions of viewers on ABC's hit show "Dancing With the Stars: All Stars," alongside her pro partner, Maksim Chmerkovskiy. This time, the duo is strictly friends, but has logged countless hours together in rehearsals and the reality-show experience has transformed her, she said.

"It was actually cathartic," she said. "I had gotten complacent."

During her first run on "Dancing" in 2011, Alley practiced eight hours a day for 12 weeks with Chmerkovskiy and shed 70 pounds. By the season finale she sweated off so much weight that her costume had to be taken in 38 inches.

Before starting the show, Alley said she felt "broken" and reluctant to be intimate.

"When I gained weight the first time and then I lost the weight, I mean, that was OK. I gained it once, I lost it," she said. "And then I gained it again, and I thought, 'Oh, Lord, is this going to be the pattern of the rest of my life?' … Maybe there were people who wanted to have sex with me, but I certainly didn't want to have sex with them in that condition."

Losing the weight and reinventing herself yet again has restored her confidence. When asked by Walters to finish the sentence, "Kirstie Alley is," she replied: "Wild."

"I think I'm wild," she told Walters. "I consider myself very eccentric. … I could honestly be sitting here with you right now while there were 10 cats jumping on the table and jumping on our heads. I think that's pretty eccentric."