Jen Garner Rejects Boyfriend John Miller's Proposal to Move in Together: 'That's Just Not an Option'

Always a mom first, Jennifer Garner turned down a proposal from her boyfriend of five years, John Miller, to move in together, RadarOnline.com has learned.

The reason behind the rejection, sources said, was so that her kids don't have to make yet another blended-family adjustment.

The three children Jen, 51, shares with her ex-husband, Ben Affleck, 50, are still adapting to stepfamily life with the Justice League actor's new wife, Jennifer Lopez.

Jen and Ben were married for 10 years when they announced their separation in 2015. They finalized their divorce in 2018.

Despite their lengthy divorce, the pair have worked hard to maintain a friendship and co-parent their three kids — Violet, 17, Seraphina, 14, and Sam, 11. The trio now has two stepsiblings in J Lo's 15-year-old twins, Max and Emme.

Ben's new marriage has allegedly been an adjustment for his children, with an insider sharing that's the reason Jen is not taking the next step in her relationship with John.

Ben's ex-wife and new bride have made peace after J Lo realized it'd be better for her marriage to have Jen on her team. "J Lo has come to accept that Jen will always be a huge influence on Ben," a tipster stated. "Even if they're not married, he still values Jen's opinion and respects her.

"While Jennifer is one of the issues that's caused recent tension in Ben's marriage, J Lo admits it helps her cause in the end."

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The source added that "instead of fighting it, J Lo's trying a new approach — to join forces with Jen and be her pal.

"It's a huge shift in strategy, but her relationship's in major trouble right now, so desperate times call for desperate measures."