With two children and half a decade of marriage under their belt, Nicole Richie and Joel Madden seemed like a snapshot of a healthy, Hollywood relationship.

But now, an insider reveals the truth to ‘In Touch Weekly’ — their marriage is crumbling, and it may be beyond the point of repair as they head towards a divorce.

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“They’re on the brink of divorce,” an insider close to the mom-of-two tells ‘In Touch.’

“They’ve been spending more time apart because all they do is fight when they’re together. Nicole can be very forceful when she doesn’t get her way, and Joel doesn’t respond to that.”

The socialite, 33, and the rocker, 36, disagree about big things, like how to raise their children, seven-year-old Harlow and five-year-old Sparrow.

nicole richie kids

Nicole and her kids on Halloween.

The insider explains, “For example, Nicole’s been on a health kick and wants the kids on the same diet. But when Joel’s around, he lets them have candy and juice boxes and whatever they want — it makes her furious.”

But staying together for the kids no longer seems worth it to Nicole, the insider alleges.

“If it wasn’t for the kids, they’d be divorced already,” the insider adds. “Nicole’s already trying to hang on for their sake, but she’s at her breaking point.”

For more on Joel and Nicole’s troubled marriage, pick up the new issue of ‘In Touch Weekly,’ on newsstands now!