Jennifer Garner’s boyfriend John Miller has a positive effect on her ex Ben Affleck. Who could have thought that a current boyfriend can even have a good influence on an ex?

According to a source, Garner’s present boyfriend and ex-husband are in good terms. So good that Miller is a good influence on Affleck as a dad, as reported by US Weekly. “Jen having a boyfriend has been the best thing to happen to Ben and Jen in a long time,” shared the insider, explaining that because of Miller, “Ben’s become a better parent.”

Garner and Affleck broke up in 2015, even though they shared three children, Violet, 13, Seraphina, 10, and Samuel, 7. They have co-parented the kids since then, but Miller coming into the picture made Afflect step up, the source said.

“He’s really showing Jen that he can be a better person,” revealed the source. “They’re coparenting in a way they never have before.” The insider added that of late, the “Justice League” star is becoming more involved in the children’s activities and taking over some of the important family responsibilities as well. Some would think this is a bad case of jealousy and insecurity pushing a person to shape up, but this is not the case at all. 

First, the source said that this is purely out of Affleck’s desire to be the best dad. “He ultimately just wants to be the best father he can be and part of that is continuing a loving relationship with Jen,” said the source. Second, he and Miller do not even have any issues with each other for one to feel triggered. The source even shared that Miller’s daughters from a previous marriage already had some “playdates with Jen and Ben’s kids” and that “Ben totally trusts him.”

This is good considering reports are claiming Miller is set to become an even more permanent figure in Garner and her kids’ lives. According to an earlier US Weekly report, the two are going to be engaged sooner than later. Their relationship is drama-free and this is a really good sign for Garner. 

On his part, Affleck could be moving on too and dating. Allegedly, he's secretly seeing Ana de Armas. 

Jennifer Garner and Ben Affleck Jennifer Garner and Ben Affleck arrive at the Oscars at the Hollywood & Highland Center on Feb. 24, 2013. Jason Merritt/Getty Images