Katie Price refused to have sex with Peter Andre for months before they split.
The former glamour model repeatedly insisted she was too tired to make love after horse riding sessions and her gruelling training for the recent London marathon.
A friend of the former couple said: "Kate loved to spice up their TV appearances by talking about their sex lives. But Pete felt uncomfortable with her boasts because he knew the truth – they weren't sleeping with each other at all."
As well as struggling with the sex ban, Peter became increasingly jealous of Katie – also know as Jordan – spending more and more time with her equestrian-loving friends.
Photos of her drunkenly flirting with other men, taken last Friday (08.05.09), while on a night out with friends from her horse riding club were the final straw, leading to his decision to split from her.
Peter is quoted by Britain's Daily Star newspaper as saying: "All she's interested in is making money and her horses. Half the time she didn't seem bothered if I was around."
He is also said to be envious at how close Katie, 30, has become to her married riding coach Andrew Gould, 28, one of the people with her on the night the photos which ended her marriage were taken.
A source told Britain's The Sun newspaper: "Peter flew into a jealous rage when he saw the photos of her horseplay at the club in Bristol. He knew she'd spent the day with her pals from the paddock - and said he couldn't trust her when she was drinking. This was the final straw."
Club manager Steve Dew said of dad-of-two Andrew: "He didn't leave her side from the time they arrived at 12.30am until they left at 2.30am. He introduced himself as her manager and was very charming. He was a lovely looking chap."
Peter, 36, reportedly made two visits to divorce lawyers over the last six months as their marriage broke down.
The pair – who are worth an estimated £50 million collectively – have a prenuptial agreement, but could still be set for a court battle.
On Monday (11.05.09), Katie fled the UK, taking the couple's two children – son Junior, three, and 23-month old daughter Princess Tiaamii - with her. Peter remains in England with Harvey, her six-year-old son from a previous relationship.