Christine McGuinness reportedly accused Paddy McGuinness of flirting with another woman, after initially being told he had kissed a separate TV star behind her back.
The mum-of-three, 34, is also said to have discovered secret Instagram messages between Paddy and a BBC presenter in March this year - prior to the pair deciding to split and end their marriage.
The Sun report that Christine was told about Paddy apparently growing close to a blonde TV star during Christine's stint on The Games earlier this year.
The former Real Housewives of Cheshire star was apparently 'hurt' when TV pals told her: "You do know what he’s been up to don’t you?"
"She tried her best to laugh off the comments but she was very hurt," the source added when discussing the claims.
The allegations come in the wake of Christine and Paddy announcing the end of their marriage on Friday, after weeks of speculation surrounding their relationship.
It has also been reported that Instagram messages between Paddy and another TV star were "one of the driving forces" for the couple deciding to go their separate ways earlier this year.
"Paddy had been messaging the woman for some time. They were direct messages and were quite friendly," a source has told the MailOnline.
"It’s unclear how they met but they followed one another for a while.
"There have been various issues between him and Christine, but this was definitely one of the driving forces that began to make them assess their future as a married couple."
The publication notes how the source added there was nothing to suggest the messages exchanged between Paddy and the unnamed star went beyond friendship, but Christine was 'upset' upon discovering them.
The Mirror has approached representatives for Christine and Paddy for comment. A representative for Christine confirmed they had "no further comment to make".
Both Paddy and Christine took to their respective Instagram accounts on Friday afternoon (July 22) to finally put an end to the speculation surrounding the state of their 11-year marriage.
Writing to her 669,000 followers, Christine explained how the decision to split had been made "a while ago" in the joint statement from the former couple.
The former model - who earlier this month revealed she and Paddy were going through a "very, very difficult" time - revealed both stars will continue to live in the family home alongside their three children; twins Leo and Penelope, eight, and daughter Felicity, five.
Rumours surrounding the state of the former couple's relationship had been prominent over recent weeks, with the former Real Housewives of Cheshire star even revealing she "didn’t cause this situation" when discussing their marriage troubles in an interview earlier this month.
According to pals of the two stars, it was known by their loved ones that the pair had been going through "difficult few years" as a couple.
A source told MailOnline: "Paddy and Christine have given everything to their marriage over the years.
"Sadly, they have made the tough decision to part ways for the sake of their young family, who they will continue to co-parent together."
The insider went on the claim: "It's been no secret within their inner circle that it's been a difficult few years for them as a couple but they still very much support each other and will continue to do so throughout their separation."
Paddy and Christine officially announced the end of their marriage via their respective Instagram accounts on Friday.
The joint statement shared by both stars reads in full: "We hadn't planned on sharing this publicly until we were ready but the lack of privacy surrounding our personal life, we feel left with no other option but to clarify.
"A while ago we took the difficult decision to separate but our main focus was as always is to continue loving and supporting our children.
"This was not an easy decision to make but we're moving forward as the best parents we can be for our three beautiful children.
"We'll always be a loving family, we still have a great relationship and still live happily in our family home together."
The joint statement continued: "We hope this now draws a line under anymore unwanted and unnecessary intrusion into our private life.
"Although we work in the public eye we ask kindly if you could respect our wishes for privacy on this matter. We'll be making no further comment."
The former couple married in June 2011 following a four-year courtship, with Paddy's comedian pal Peter Kay acting as the best man on their during special day.
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