Keating cheated on his partner with 27-year-old Francine Cornell, who worked as one of Boyzone's backing dancers in 2009. The affair lasted seven months before texts were discovered on his phone.
Cornell later claimed that it was the singer who had chased her and had messaged her persistently.
He and Yvonne, 38, separated soon after the adultery but briefly reconciled. However, the couple could not work through their problems and divorced in April of this year.
Ronan admitted in an interview with Magic 105.4: "It's been a tough couple of years - I deserved what I got."
The pair have remained friends for the sake of their three children, the youngest of which is 6-year-old Ali.
Ronan also revealed in the interview that his 11-year-old daughter may follow him into showbiz.
"Missy made a film this year, which is coming out in February; a horror movie called Dark Touch," he explained.
The Boyzone frontman is currently a judge on the Australian version of The X Factor.
Watch Keating perform a medley with his fellow X Factor judges below: