Despite forming an unlikely bond with KP in the CBB house, Katie doesn't have anything nice to say about her housemate's third hubby.
Writing in her column with The Sun today, Katie has slammed Kieran for cheating on KP with two of her friends.
She said: "Kieran is a cretin. Being unfaithful to your wife is one thing. Doing it with her best mate in the stable block while she is trying to give birth is another."
In her musing, written while in the CBB house, Katie has also revealed that KP has asked her to write her speech for her forthcoming vow-renewal with Kieran.
The couple, who married in the Bahamas in January 2013, are planning a lavish second wedding in the coming weeks and KP wants to address her husband formerly on their big day.
But directing her column at Kieran, KH added: "When your beautiful wife stands up to tell you why she is giving you a second chance, be clear - I wouldn't give you so much as a smile."
Wow, we'd love to hear that speech!
KP was a late arrival into the CBB house last Friday and, at first, it was presumed she and KH would not get on. In the past, Katie H hasn't had many nice things to say about the Pricey, insulting both her choice of name for daughter Bunny and her appearance.
However, as the women have got to know each other, they have become close. Earlier this week, Katie P even made Katie H cry after saving her from nomination.
The Pricey told KH: "Before I came in the house, no one would have ever thought we would get on. Yes, you're very opinionated and not everyone likes what you say.
"You never say opinionated things that are nice, you only ever say opinionated things that are horrible.
"But being in the house with you has been nice and refreshing and we've been able to talk about normal things. I love your humour, you're right up my street and I'll definitely be your friend out of the house.
"I think you're really funny, witty, family-orientated and you've got a heart. I don't actually think there are that many bad bones in your body."
As a result, Katie H no longer faces eviction tonight. Instead, Katie P replaced her with Calum Best and he is going head-to-head with Alicia Douvall, Nadia Sawalha and Perez Hilton.