"They were physically separated and emotionally," one Paltrow insider said, while another added: "They have been on and off for many years."
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When they announced their split in a statement on Gwyneth’s website, the pair stated that "in many ways we are closer than we have ever been". That certainly seemed to be the case as less than a week later the pair were pictured together in the Bahamas with friends.
The separated couple – who said "we will always be a family", – took their children Apple and Moses away on holiday before breaking the news that they're no longer together.
The pair had notoriously spent the majority of their decade-long marriage avoiding being photographed together, with only a handful of snaps being taken since 2003.
Speaking to People magazine, a close friend of the actress confirmed that the "marriage was falling apart", as a third friend told the magazine that Chris, the lead singer of rock band Coldplay, "is the kind of person who is always in a T-shirt. She's much more glam."
Gwyneth has steadily maintained a career in Hollywood and has spoken of her desire to keep her two children, Apple and Moses, out of the spotlight.
Gwyneth and Chris in 2003
A source continued: "They seemed to have a pretty mature handle on that crazy rotation of being superstars and parents. But that balance, given the time they had to spend apart, clearly couldn't sustain itself."
Gwyneth has previously spoken about how hard marriage can be, admitting that the couple have gone through "terrible times".
"It's hard being married," Gwyneth said to Glamour magazine. "You go through great times, you go through terrible times. We're the same as any couple."