Ben & Jen Coparenting Better Than Ever — All Thanks To Her Man!

Ben Affleck and Jennifer Garner have both moved on after their marriage imploded, and they’re finally a united front when it comes to raising their kids!

“Ben and Jen are playing happy family at last, only this time they aren’t acting,” a source exclusively revealed to RadarOnline.com of the former couple’s dedication to Violet, 13, Seraphina, 10, and 7-year-old Samuel.

And the pair's parenting solidarity all has to do with 47-year-old Garner’s guy, businessman John Miller!

“Jen having a boyfriend has been the best thing to happen to Ben and Jen in a while,” the source said.

Miller, the 41-year-old father of a daughter who has gone on play dates with Garner and Affleck’s kids, seems to be a great influence and example for Affleck, 46, to follow.

“Ben’s a better parent now, and he has no problems with John and totally trusts him,” noted the source, explaining, “He has seen him interact with the children.”

“Ben is showing that he can be a better person than he was,” the source added. “He is taking over school activities for the kids and they are co-parenting in a way that it’s never been before.”