JENNIFER GARNER exploded after hubby BEN AFFLECK  blabbed about staying in touch with ex-fiance JENNIFER LOPEZ – and now she’s keeping him on a tight leash!

Furious that he’d gushed over her love ri­val J.Lo, Jen arranged to leave the couple’s three children behind while they jetted to Paris for a romantic getaway, sources say.

“After Jen read Ben’s glowing comments about Jennifer, she hit the roof,” said an in­sider. “She screamed at him that he’d made her look like a fool.

“Jen’s always felt threatened by Ben’s passionate relationship with J.Lo. So hearing him rave about her really struck a nerve.”

The Academy Award-winning star, who’s getting Oscar buzz for his political thriller “Argo,” was set to marry Lopez in September 2003. The couple called it off, but Ben admit­ted keeping in contact with the Latina hottie in a recent interview.

“We don’t have the kind of relationship where she relies on me for advice, but we do have the

 kind of relationship where there’ll be an e-mail saying, ‘Oh, your movie looks great,’” the 40-year-old actor/director said.

“I touch base. I respect her. I like her…and I’m really pleased to see her successful.”

That sent Jen – whose last three movies, “Butter,” “The Odd Life of Timothy Green,” and an “Arthur” remake, all flopped – into a tailspin, said the source.

“Jen’s been feeling down on herself, and Ben’s thought­less comments didn’t help,” revealed the source.

So while Ben made plans to head to Paris to promote “Argo,” Jen secretly arranged for her mother to baby-sit the couple’s 8-month-old son Samuel and his big sisters Violet, 6, and Seraphina, 3.

“Ben thought he was heading to Paris solo until he saw Jen’s bags at the door,” said the source.

The couple flew to Paris aboard a private plane on Oct. 14, and a smiling Jennifer, 40, was soon spotted shopping at high-end boutiques such as Chanel and Isabel Marant.

She and Ben, 40, also shared a romantic dinner at La Fontaine de Mars restaurant before he headed off for more European premieres and she flew back to L.A.

As The ENQUIRER has reported, the couple has battled in the past over his smoking habit, his gam­bling and being separated due to his heavy work schedule.

“Every now and again Jen needs to crack the whip to get Ben back in line,” said the insider. “She knew a trip to Paris would be good for both of them.”