Weinstein's television appearance today follows reports that Madoff is dying of cancer -- reports that have since been dispelled by the U.S. Bureau of Prisons.
Weinstein says her long relationship with Madoff has given her insight into how he could have defrauded thousands of people, including many who were close to him.
"I think it was more important to Bernie to keep up the façade, the image at all costs … no matter what the moral implications," she said. "It was about Bernie and who Bernie had to be to the world."
That desire "could have stemmed back to his childhood," she said, adding that isn't an excuse for his actions.
In the book, Weinstein also divulges personal details about the man she referred to as "Mr. Winky Dink" because of a funny face he would make.
"It was just a code name between me and a friend or two that was aware of the situation," she said.
She added that "he was a good kisser. Very nice."
As for her view of the relationship, Weinstein said, "I didn't like being second. I didn't like playing the back room type of person."
She says Madoff was afraid of what would happen if his wife, Ruth Madoff, learned of their affair.
"He was petrified of Ruth … of his wife finding out," she said. "Divorces or something like that leads to books being opened … something might come out."
When asked if she had a message for Madoff, she said she wanted him to know that the victims of "this immense human tragedy ... will survive."
And, she added, "he shouldn't have stolen money from somebody you have a relationship with."