Halle Berry and Olivier Martinez reportedly had huge arguments about where to raise their two-year-old son, Maceo.
The 'Extant' actress, who filed for divorce from the French actor today (27.10.15) after two years of marriage, didn't see eye-to-eye with him about a lot of things, including about whether they should live in Los Angeles or Paris.
A source told PEOPLE.com: "Olivier never loved living in L.A. full time. [He] just isn't happy in L.A.
"They have had many issues. They both have fiery personalities and don't like to compromise. Halle has threatened to file for divorce several times after arguments."
The Oscar winner was legally blocked from moving to the French capital with her seven-year-old daughter, Nalha, by a judge in 2012 during a bitter custody battle with her ex-boyfriend Gabriel Aubry, but Olivier, 49, has continued to divide his time between both cities.
Another source told E! News: "They have had long stretches of time apart and both seem happier when they don't have to deal with the other. They have a lot of differences culturally and as far as lifestyle goes. Things didn't jive between them and they grew apart. It was a challenge to meet each other's needs and be on the same team."
While the 49-year-old actress "had an incredibly passionate bond" with Olivier and they initially attempted to save their marriage, they're now both ready to move on.
The source added: "They've essentially been separated for several months, but now they are both ready for a clean break and to move on with their lives.
"They have struggled for a long time and had been living separate lives. They waited it out for a while, seeing if things would improve, but they didn't."