Since their split was announced yesterday, it has transpired that Katie's wild partying ways drove Peter to end their relationship.
The orange reality TV ex-couple were known for their occasional fights - but a particularly nasty one aired recently in the UK that suggested all was really not well in their marriage.
The fight began when Peter wondered aloud whether a shop assistant in Hollywood recognised his famous UK customers - and got cut down by his wife pronto.
After calling Peter a "f****** knob" she can't stand", she fired, "no-one knows who you are, you’re an old f****** singer no one knows about."
Peter responded by calling her a "stupid, miserable, arrogant cow."
When Peter complained that Katie always got her own way, she cruelly responded with, "I'm the one making the money Pete, so of course I can have it how I want."
A peeved Peter replied, "What, don’t I make money?"
Katie said, "I don’t know, do you? Hurts, doesn’t it?"
Just before the fight was broken up by their manager, Peter fired, "You know what? You really, seriously, seriously are a psycho. I hope you are f****** proud of yourself."
Ouch! Somehow we think their children will be better off without this kind of warfare in the home...
Katie recently spoke out about their split, saying she is "devastated" and that “Pete is the love of my life — and my life.
“We have children together and I am devastated and disappointed by Peter’s decision to separate and divorce me — as I married him for life.
“This is not what I want and the decision has been taken out of my hands.
“I will not comment further or do any interviews regarding the separation. But I will always love my Pete.”
The Sun quote Peter as telling a friend he was "so unhappy" with Katie.
“Katie has everything she could ever want — look at our beautiful children," he reportedly said to a pal.
"She’s got a multi-million pound career and a dream home. But it’s like she is insistent on pressing the self-destruct button.
“She is the most lovely woman when she is being just herself and I will always love her. But in the end, it all got too much to handle.”