The actress, 46, who heroically performed an intervention and drove her ex-husband, also 46, to rehab in August, is now laying down the law on his personal life, a source said.
And that's happening even as Garner is romancing a new man who is still married and locked in a bitter divorce!
"Jen is trying to ban Ben from dating," the insider told Radar. "She's given him an ultimatum to quit seeing women and focus on staying sober."
As Radar readers know, the Justice League actor had a sobriety setback this summer and went into treatment.
Affleck recently told fans he completed his latest stay in rehab for alcohol addiction, saying he's "fighting for myself and my family."
Garner and Affleck's divorce was finalized on October 5—three years after the couple's shocking split.
Affleck put the Peppermint actress through the wringer but she's now moving on with a new boyfriend, businessman John Miller, as Us Weekly first reported.
Radar exclusively confirmed the CEO is still legally married — and in the midst of a nasty divorce.
Miller, 40, and his estranged wife Caroline Campbell have been locked in an ugly battle since first calling it quits on their six-year marriage in 2011. In court docs, Campbell called him "controlling."
But in the midst of the controversy over her new beau, Garner still cares about her ex Affleck and wants him healthy for their three children-- Violet, 12, Seraphina, 9, and Samuel, 6.
And that means she's banning babes for Ben!, according to the source.
Garner was horrified by Affleck canoodling with Playboy model Shauna Sexton in Montana right after their divorce was finalized.
The actor and Sexton, 22, split up soon after their hot getaway.
The insider told Radar that Jen is now "putting Ben over her knee and scolding him like a child after his awkward breakup with Shauna.
"He’s a big baby -- but Jen’s telling him to man up and sober up because he’s got no one else to blame but himself."
According to the source, bighearted Garner is "not holding the kids as leverage but that’s the meaning behind her tough love approach - if he stays sober he’ll get more time with them.
"Ben’s mom is behind it, too, but Jen’s taking the reins. She’s wearing the pants and is very in control of the situation.
"Ben knows he’s got to follow her lead because he messed up so royally."
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