Carrie Underwood & Husband Mike Fisher 'Bickering' & 'Butting Heads Nonstop' Since Singer Returned To Work: 'He's Running Out Of Patience With Her'

In crisis mode!

So much for starting the year on a high note: A source tells OK! Carrie Underwood and hubby Mike Fisher have hit another rough patch in their roller-coaster romance.

While the couple had a chance to reconnect during lockdown, a source says Underwood's back to focusing on her career, and it’s causing “strain” at home.

The couple, who share sons Isaiah, 6, and Jacob, 3, spent much of lockdown tag-teaming on parenting duties, but now with the "Before He Cheats" singer hard at work on her "Reflection" residency in Las Vegas, the retired hockey pro has been left to pick up the slack.

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“They had a good routine going during the pandemic when they were spending so much time together as a family,” shares the source. However, since the Grammy winner hit the stage again, they’ve been struggling to get back on the same page.

“They’ve been bickering and butting heads nonstop,” spills the source, “and it’s not pretty.”

While the country star, 38, has always run a tight ship on the home front, lately, she’s been “super stressed” with the pressure of nailing her first residency, notes the source, who says she’s taking it out on her hubby, 41.

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“She’s turning up the heat on poor Mike,” explains the source. “The word is she nags at him about everything from letting the kids eat junk to not picking up after himself. On the surface, it’s small stuff, but it builds up and then she explodes.”

According to the insider, tensions came to a boiling point ahead of the American Idol alum's March 10 birthday.