Jennifer Garner is just a concerned ex. The actress is “cautious” about her ex-husband Ben Affleck’s fast-moving relationship with rekindled flame Jennifer Lopez, a source exclusively reveals to In Touch.

The insider claims that Garner has “nothing against J. Lo” and she “thinks [J. Lo] is good for him.” However, she’s nervous “about how fast it’s moving.”

Ultimately, the insider says the 13 Going on 30 star, 49, is “really happy for Ben,” adding, “When he’s working on films, happy in his personal life, and working his AA program, she can sleep at night. “

“Ben’s a really good man and he’s a great father, she can never take that away from him. The kids adore him,” the insider says. Ben, 48, and Garner share three kids — daughters Violet and Seraphina, and son Samuel.

On June 9, the Alias actress was spotted taking Samuel to the beach while the Good Will Hunting star hung out with J. Lo’s mother, Guadalupe Rodríguez, in Las Vegas. Ben was spotted at the Wynn resort where he is filming a new project while the Hustlers actress was in Miami.

Ben and the “Dinero” singer first sparked rumors that they were back together in April following the latter’s split from baseball player Alex RodriguezIn Touch confirmed that Jennifer and Ben were an item on May 26.

Jennifer Lopez Dating History Alex Rodriguez

A separate insider previously told In Touch that J. Lo is eager to relocate closer to Ben and away from any “reminders” of ex Alex, 45.

“The timing right now is perfect, meaning Ben, she wants to be closer to him in Los Angeles,” the source said. “She’s all about starting fresh, with a clean slate, which she also applies to her relationships. Now that she and Ben are together, they’re definitely moving towards building a solid partnership. A new home is a must for her.”

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