Yesterday, the couple announced that they had split after 12 years of marriage. They have three children together - Jack, 11, Marie, 9, and Ali, 4.
According to The Mirror, the decision to separate was made by Yvonne after the Boyzone star confessed that he had been unfaithful.
A source told the newspaper: "Yvonne was heartbroken but she made her mind up on the spot. The cracks were there already, but this was the final straw. She isn't the sort of person to forgive and forget. Ronan has accepted her decision."
Keating is alleged to have cheated with a dancer while away on a recent solo tour. The woman in question is said to be planning to sell her story.
The insider added: "It was during these nights away from home that he's thought to have strayed. It's a lonely existence being on tour with lots of late nights. Sadly, the temptation proved too much."
A spokesperson for Keating refused to comment on the reasons for his marriage break-up.