It seems Naomi Watts and Liev Schreiber's split was a long time coming!

According to a new report, the former duo "have been on shaky ground for years."

"They split because she wants to travel the world, making movies and attending film festivals and red carpets. But he is a New Yorker and just wants to settle down with their kids," an insider close to the pair told OK!.

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Naomi and Liev in September 2016.

The source additionally revealed Naomi had many suspicions about Liev's relationship with their family nanny throughout the years. "Liev told Naomi time and again that she was being ridiculous, that there was nothing going on. But she was never sure," the insider added.

MORE: Liev Schreiber Gives a Sweet Shoutout to Naomi Watts Just a Few Days After Their Split — See What He Said!

Naomi, 48, and the Ray Donovan star, 49, first became an item in 2005 and welcomed two sons — Sasha, 9, and Samuel, 7 — together before confirming their separation on Sept. 26.

Click through the gallery below to see more shocking celebrity splits!