A source told The Mirror: 'Word got back to Stacey that Ryan had been flirting with some of the waitresses at George's, and she had had enough.'
The Sun report that neither party will be in attendance when the decree nisi is granted at Central Family Court in London.
Giggs, who stands to lose a share of his fortune, initially argued that he made a 'special contribution' to the creation of wealth during his marriage to estranged wife Stacey.
A judge overseeing the dispute at hearings in the Family Division heard that Giggs would call witnesses to support his 'special contribution' claim at any trial.
Specialist lawyers said that millionaires must show that they have a spark of 'money-making genius' to persuade divorce court judges to give them the lion's share of a marital fortune.
Experts said the special contribution argument which Giggs is expected to rely on is unlikely to be successful simply where someone is very good at their job.
Instead, that person must show they have the 'X Factor' to persuade judge to avoid simply splitting the pot in two, they said.
Lawyers told Mr Justice Cobb that Mrs Giggs would call witnesses in 'reply'.
Jo Edwards, an expert in family court litigation, said: 'Whilst big money is necessary to try to mount a special contribution argument, big money is not enough to succeed; you also have to establish that the contributor has that X factor, that spark of genius.'
The judge said the public should not be given detail of private financial information and he says the names of the estranged couple's children should not be revealed in reports of the case.
He outlined his thoughts in a written ruling on how the case should be reported.
'The husband was a professional footballer,' said Mr Justice Cobb. 'He has a number of business interests, and has (had) a role in coaching and management.
'He played football nationally and internationally for many years, and has a high media profile. He is now 43 years of age.
'His marriage to the wife came to an end last year. The husband and wife have two children. This information is well known to the public at large.'
He added: 'This couple have a significant profile in the media, both nationally and internationally.
'That they are divorcing, and that their financial remedy proceedings are being pursued in the English courts, are pieces of information already in the public domain, and the publication of that information cannot legitimately be restrained by order.'
But he said it was 'appropriate' for hearings be to be staged in private.
