In an unbelievable act of cold cruelty, the father of Katie's baby son Jett and expectant dad to their unborn daughter has shouted his mouth off to a newspaper about his affair with the former model's best friend, Jane Pountney. Perhaps he should be re-named Loud Hayler.
In The Sun on Sunday, Kieran goes into agonising, warts 'n' all detail about how his fling started with a kiss while Katie lay in hospital after giving birth to Jett – and then developed into a full-blown affair, with the cheating pair having sex in Katie's stables.
Wringing every last coin from his five minutes of fame-by-association, the former male stripper feigns contrition by telling the paper: "What I've done is worse than bad. Kate's done nothing wrong. She's been an amazing wife but I've almost ruined her - she's an absolute mess."
Which is quite possibly the understatement of the year.
Kieran, 27, and Katie, 36, were holidaying in the South of France last summer with Jane and her husband Derrick when Katie's waters broke early and her unborn baby's heart-rate fell dangerously low. Katie spent two weeks in hospital before having an emergency Caesarean to give birth prematurely to 5lb 2oz Jett.
But while she recovered alone her husband and 49-year-old best friend were beginning a secret affair.
LIKE PARENTDISH ON FACEBOOK
Recalling that first kiss, Kieran told the paper: "I took a risk and pulled Jane towards me in the kitchen of the villa where we were staying in France while Kate went to do a night feed.
"It was awkward but we kissed and I knew she was the one who could give me what I needed. Within weeks we were having a full-blown sexual affair.
"Kate's waters broke two days into our holiday. She was alone in a hospital room and I could have been there but I wasn't.
"Jane's husband Derrick eventually returned to England and I was spending more and more time with Jane at the villa.
"We were chatting a lot, getting to know one another. My phone had broken and Kate was sending Jane messages asking her to tell me to go to the hospital - but she wasn't showing them to me.
"I had injured my shoulder on a quad bike and she kept telling me to rest, saying, 'Kate will want you to look after yourself, to be strong for when the baby comes'.
"She was also saying things like, 'You're just another guy to Kate and she treats you like s***.' "
After their kiss in France, the pair went on to have sex several times over a seven-month period.
But they were caught out when mum-of-four Katie saw them kissing last month during a holiday to the Atlantic island of Cape Verde.
The cheating pair and their spouses spent another eight days marooned at the holiday resort before they could get a flight home.
When they arrived back home, Katie that she was divorcing her 'disgusting' husband and tweeted: "Sorry to say me and Kieran are divorcing. Him and my best friend Jane Pountney have been having a full-blown sexual affair for seven months."
But despite everything, Kieran, who currently sleeps in the spare room of his marital home, remains convinced he can save his marriage.
He said: "We need to bring our baby up into a happy house. I am blaming myself a lot and I hate Jane. I feel like she is the one who has done this to the family.
"She made me do this. She didn't say, 'No'. She was meant to be Kate's best friend and she didn't even apologise. Kate's supposed to be having bed rest as there's a risk our baby could be born prematurely again, but she's so stressed.
"That's the bit that kills me. I've broken her. I'm going to try to save my marriage but I've almost ruined it. Kate has been an absolute mess. She is focused purely on her children and pregnancy - I have no idea if she will forgive me."
Hmm, after this latest betrayal, let us hazard a guess...
More on Parentdish: Wronged husband to divorce Katie Price's former best friend