Nicole Richie and Joel Madden's marriage is officially on the rocks, and In Touch can reveal exclusive details behind the reason for their crumbling relationship.

According to a source, the couple's six-year marriage has been on thin ice due to Nicole's hectic work schedule, which intimidates the Good Charlotte singer.

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"They have been arguing lately because Joel feels Nicole is working too much," the source revealed. "Joel has had a successful music career with his band, but Nicole’s become the family breadwinner. That leaves Joel feeling threatened.”

nicole richie, joel madden

Unfortunately, being a stay-at-home mother to children Harlow, 8, and Sparrow, 6, just isn't in the cards for the 35-year-old, who is currently in between running her successful fashion line, House of Harlow 1960, and filming new content for her AOL series #Candidly Nicole.

“Things are rocky," the source continued. "Friends and family are hoping they can get through this.”

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The mother-of-two sparked rumors of divorce after stepping out without her wedding ring just before Christmas. A different source previously revealed the couple had been experiencing trouble in their relationship for over a year.

“Nicole and Joel are basically living as co-parents right now,” a source told Radar Online. “They had a super rough year and right now they are really trying everything imaginable to salvage what is left of their marriage.”

To fuel divorce rumors even more, Nicole was also spotted getting very cozy with a mystery man while her husband was in Australia filming The Voice (AU).

nicole richie joel madden getty images

The couple began dating in 2006 and were engaged in 2010. They married a year later at Nicole's father Lionel Richie's Beverly Hill estate.

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