The `Beautiful` hitmaker - who married Jordan Bratman in 2005 , three years after they met - is reportedly living apart from the music executive, though they have not yet decided whether to divorce.
A source said: "They are now living apart, and they will see how that goes."
According to friends of the couple - who have a two-year-old son Max - there was no major incident that triggered the split, but they had grown apart in recent months and attempts to revive their relationship had failed.
The source told Usmagazine.com: "They were very much in love. But over the last six months, it became clear they were more like friends than husband and wife.
"Christina even proposed their August trip to Italy to rekindle their relationship, but it didn`t help."
Despite their separation, the couple are continuing to focus their attentions on Max, with the 29-year-old singer even taking him to the recording studio with her while she works on the soundtrack to her forthcoming movie `Burlesque`.
The insider added: "He is their main concern.
"Christina is doing her best to be a great mom. She has a lot to juggle, but she`s learning how to make it work and balance it all."