THE ex-mistress of “To Catch A Predator” host CHRIS HANSEN is finally breaking her silence about their steamy affair – two years after they were exposed by The ENQUIRER!

In a bombshell “open letter” penned exclusively for The ENQUIRER, sexy TV reporter KRISTYN CADDELL blasts her former illicit lover as a cad who not only lied to his wife but to her as well. She also blames him for ruining her once promising career.

Caddell, 32, says she met the 53-year-old “Dateline NBC” correspondent in a Palm Beach, Fla., bar in March 2011, and he led her to believe his nearly 20-year marriage was on its last legs, so he was free to date.

“Chris told me a divorce was inevitable and the wedding ring on his finger was all but for show,” Caddell recalls in her scathing letter.

“Over the next several months, our friend­ship evolved into a whirlwind romance. As far as I was concerned, none of it was being done secretively or concealed from the public.”

Hansen flew her all over the country, and the couple stayed in “the finest hotels,” according to her letter. They had dinner and mingled “with many of his colleagues,” and Caddell supplied The ENQUIRER photos of the two of them together in public places.

Caddell claims she didn’t learn Hansen was lying about his marriage until just before The ENQUIRER’s exclusive report of the cheating scandal was published in our July 11, 2011, issue.

And now, sources say, Caddell’s full admission to The ENQUIRER may spell the death knell to Hansen’s marriage to wife Mary as the predator catcher’s lies have been exposed..

For the FULL STORY with all the details and to see the EXCLUSIVE PICTURES of Kristyn and Chris TOGETHER – pick up the new ENQUIRER – on sale NOW!