The couple decided to give their marriage another go after it emerged that Kieran had cheated on Katie with two women - Katie's best friend Jane Pountney and pal Chrissy Thomas - but TV star is adamant she's dealing with the drama in a mature fashion.
Katie, 36, explained: ''I can be the most devious person in the world but I'm not interested in revenge. Two wrongs do not make a right.
''There's always the threat of a lie detector but Kieran's not worried because he has nothing to lie about. I don't want to build up the trust and have a strong marriage.''
However, Katie says that although she's determined to make their marriage a success, she will not give Kieran - with whom she has two children, 12-month-old son Jett and an as-yet unnamed baby daughter - another chance if he slips up again.
But she has been impressed by the progress he's made with his sex addiction in therapy.
Katie said: ''Some people say it would've been easier to walk away but I wanted to stay and make a go of it.
''I'll never forget what he did and this is his last chance - if he did anything else, I'd be off - but Kieran's changed so much. He's continuing with his therapy and is happy.''
However, Katie is going to document the affairs and what she went through in a new autobiography.