The former Cheers star makes the revelation in her new memoirs The Art Of Men, revealing she was so immature when she first came to California with her childhood sweetheart Bob Alley that their marriage had no chance of surviving.
She tells U.S. news show Entertainment Tonight, ""I s**ewed up the relationship... I was sort of lost. I knew how worthless I was.
""We dated for four years before we were married and I was so immature... I stayed 16 through the whole marriage and when we moved to California I was flirting with guys on skateboards. I sort of went crazy... I was getting a lot of attention.""
The marriage finally fell apart after Alley fell in love with a man named Jake.
She recalls, ""I always say that what I did was worse than cheating because when I met Jake, I didn't have sex with Jake, but... I think it's worse when you fall in love with someone else... and you're plotting and planning.
""What I did do with Jake was I kissed him and in my world, in Kirstie world, that meant I had to get a divorce, because that was unethical and that was infidelity to me... I was a horrible person; I destroyed my marriage.""
Alley and her first husband were married when she was 16 in 1971. They divorced in 1977.