The famous couple have very different parenting styles with Jolie being more relaxed and Pitt often frustrated.
Angelina Jolie Pitt and Brad Pitt separated just five days ago, according to the divorce filing obtained by PEOPLE.
Jolie filed from divorced from the 52-year-old actor on Monday, after two years of marriage.
They sometimes clashed over issues of raising their children, the source says.
“They always had disagreements when it came to disciplining the kids,” according to the source. “With all the kids, it did tend to get chaotic many times.”
Pitt “has always been stricter,” the source adds – claiming The Big Short-star “wanted the kids to have more structure” and “was more about having rules.” While the source said he never used any kind of physical discipline, Pitt was known to “get frustrated sometimes and yell at the kids.”
That parenting style was different than Jolie’s.
“Angelina always had a more relaxed attitude when it came to the kids. She definitely never yells,” according to the source.
Just last month, sources told PEOPLE that the couple were “as happy as ever.”
“They really are great,” the source said. “They’re really busy, but happy. The kids are getting so big! It’s hard to believe.”
Pitt and Jolie first met on the 2003 set of their 2005 thriller Mr. & Mrs. Smith, and began publicly dating a few years later – after the actor’s split from then-wife Jennifer Aniston.