The Boyzone singer’s relationship with backing dancer Francine Cornell had reportedly become an “open secret” and she had told her friends about the romance.
A source told The Sun newspaper: “Francine had become quite indiscreet. She told more than one friend this year she couldn’t date other men as she was with Ronan.
“It was as if she wanted people to know. By that time they’d been having an affair for months – it had become an open secret in the dancing community.”
Francine even dumped her previous boyfriend Nick Robbins in October 2009 when things began to get more intense with Ronan.
Nick’s dad Royston told the Daily Mirror newspaper: “I think they’d discussed marriage. She moved into his Chelsea flat and was really pleased when she began working for Ronan.
“Nick told me she was already receiving texts from Ronan. Next thing I heard, she’d told Nick that she wanted to end things.”
Meanwhile, Ronan kept a low-profile between performances in Switzerland over the weekend.
A backing dancer for the ‘Life is a Rollercoaster’ singer said: “We’ve hardly seen him and he’s hardly said a word.
“As soon as he came off stage on Saturday (22.05.10) he just said, ‘God, that was tough – I just want to go home.’ ”
The 33-year-old singer – who has three children, Jack, 11, Marine, nine and Ali, four, with his model wife – is now heading back to Dublin to try and reconcile with Yvonne, who threw him out of the family home last week following the affair revelations.
A friend said: “He’s in bits – embarrassed and ashamed. He’s saying he’ll do whatever it takes to get Yvonne back. He’ll beg on his knees.”
However, a pal of Yvonne’s said she is unlikely to give into him easily.
The source said: “She isn’t going to crumble on this. They had a pact never to cheat. Ronan really has little hope of saving the marriage.”