The couple, who recently welcomed their second child together, are said to have made the statement in a public declaration in front of family and close friends.
According to Monday's The Sun (25 August), the pair spoke at a family gathering and said they had survived a lot of "s**t" but that they are now a "stronger family than ever".
In May, a pregnant Katie swore to divorce her husband Kieran after she caught him cheating on her with (now ex-) best friend Jane Poutney.
But the former glamour model has since mellowed and chosen to forgive him.
A family friend told the newspaper: "The new baby has melted Katie's heart and she made a big public show of recommitting themselves to each other.
"Kieran got quite emotional and said his family was his everything. Everyone hopes, for Kate's sake, he's for real this time."
Katie is now a mum of five after giving birth to a baby girl on 4 August.
She has been characteristically vocal about her heartbreak and how she's struggled to come to terms with Kieran's infidelity and his therapy for sex addiction.
However, Katie hasn't been quite so forgiving towards her former friend Jane, who she recently called "scum" on Twitter.
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