Mary-Kate Olsen has now officially filed for divorce from Olivier Sarkozy, and a source is speaking out about the "final straw" which motivated her to end their marriage.

Olivier wanted to move Charlotte Bernard and their kids into his Bridgehampton home with Mary-Kate, but the 33-year-old fashion designer and former actress felt "it was too much to have his ex-wife living with them."

Olivier Was Worried About The Safety Of His Family

A source recently told Page Six that the relationship issues between Olivier Sarkozy and Mary-Kate Olsen became unmanageable after the French banker started expressing concerns about the safety of his family in New York.

"He insisted to Mary-Kate that he wanted to bring his ex-wife, their kids and his mother from the city to their Bridgehampton home,” stated the source.

Mary-Kate Didn't Want To Live With Her Husband's Ex

The source added that while Mary-Kate loves Olivier's children with Charlotte Bernard, "it was too much to have his ex-wife living with them during the pandemic."

"Would you want the ex-wife living with you for an unforeseeable amount of time in the middle of a crisis," the source asked.

According to a second source, Olivier's mother, children and ex-wife moved in with him as soon as Mary-Kate moved out in April, "to keep them in a safer place, away from COVID.”

RELATED: Inside Mary-Kate Olsen’s Ironclad Prenup

Mary-Kate Was Finally Able To File For Divorce This Week

Mary-Kate filed an emergency petition to file for divorce from Olivier earlier this month, but was denied after the court decided their split wasn't an emergency. The moratorium on non-emergency divorce filings was lifted on Monday, so she officially filed for divorce that same day.

NEXT: The Real Reason Behind The Mary-Kate Olsen- Olivier Sarkozy Divorce