Say it ain't so!

Ben Affleck and Jennifer Garner may seem like the world's best co-parents, but behind closed doors, the tension is unbearable.

Since filing for divorce back in April, multiple sources confirm exclusively to In Touch that Ben's been stirring up drama — questioning Jen about her personal life and meddling with the kids' schedules.

"Ben is very upset that the divorce is proceeding," and at times is not civil, an insider reveals. "Pals say Ben is angry and jealous because he’s no longer the center of Jen’s world, and Jen’s fed up.”

Ben recently "decided at the last minute he couldn’t pick up the kids from school and wanted to do it the following day," says the insider. “But Jen refused to accommodate Ben because she’d already made plans for them after school. There is a schedule in place for a reason, and Ben needs to abide by it.”

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ben affleck jennifer garner

(Ben and Jen spotted leaving church with their kids in April 2017. Photo Credit: Splash)

The usually civil exes frequently attend school events together — including a fifth-grade presentation on June 7 and an ice cream social on June 8.

“Jen’s adamant about protecting the kids Violet, 11, Seraphina, 8, and Samuel, 5, from her and Ben’s messy divorce and doesn’t want to give the parents at school anything to gossip about,” says the insider.

Yet Ben, 44, is living the bachelor lifestyle, and Jen is furious.

His home is "set up like the ultimate bachelor pad, and it’s not very child-friendly," says the insider, adding that Ben’s luxurious gated, modern house “reeks of becoming a mini–Playboy Mansion. He’s even been asking friends to bring over hot starlets for parties.”

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Meanwhile, Jen, 45, has been spending more time with her girlfriends.

“She’s been enjoying evenings out with girlfriends, which hasn’t gone down well with Ben,” says the source. “Ben bombards her with questions about what she’s up to. His jealous behavior drives Jen crazy because she’s doing nothing wrong, and what she does in her personal time is none of his business.”

The insider adds, "She’s gone above and beyond to make the divorce as amicable as possible. For Ben to now act like a spoiled, selfish child, creating all of this drama…she’s seeing red.”

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