Jennifer Garner’s boyfriend John Miller ‘isn’t thrilled’ about her ‘growing bond’ with ex Ben Affleck: ‘Feels like a third wheel’

Jennifer Garner’s longtime boyfriend, John Miller, “isn’t thrilled” about the actress and her ex-husband, Ben Affleck, spending more time together, a source exclusively tells Page Six.

Miller “knows Ben and Jen have been leaning on each other more than ever lately and have a really close relationship.”

“Their growing bond is getting to be a bit much when Ben spends all the holidays with them like Christmas and Thanksgiving,” the insider says. “John feels like a third wheel.”

Jennifer Garner’s longtime boyfriend, John Miller, “isn’t thrilled” that the actress and her ex-husband, Ben Affleck, have been spending more time together, a source exclusively tells Page Six. Felipe Ramales / SplashNews.com Miller “knows Ben and Jen have been leaning on each other more than ever lately and have a really close relationship,” the insider says. GC Images The source tells us, “John feels like a third wheel.” BACKGRID

According to the insider, the Oscar winner and the Emmy nominee, both 52, “text, call, and communicate far more than they have over the past several years.”

“It used to be solely about the kids, but John feels like it could be more than just about their coparenting relationship,” the insider says.

“He doesn’t feel threatened in terms of Jen ever getting back with Ben, but at the same time it’s hard not to feel jealous when it’s clear they have a strong connection and friendship.”

“Their growing bond is getting to be a bit much when Ben spends all the holidays with them like Christmas and Thanksgiving,” according to the insider. BACKGRID The Oscar winner and the Emmy nominee “text, call, and communicate far more than they have over the past several years,” our source tells Page Six. GC Images “It used to be solely about the kids, but John feels like it could be more than just about their coparenting relationship,” the insider says. ZapatA/MEGA

The businessman, 47, and the “13 Going on 30” actress have been dating on and off since 2018. 

Garner and Affleck — who were married for 10 years, from 2005 until 2015 — coparent their three children: Violet, 19, Seraphina, 16, and Samuel, 12.

Earlier this week we reported that the former couple have been “spending more time together” and “are closer than they’ve ever been since their divorce.”

“Particularly since Ben’s divorce from Jennifer [Lopez] and with the LA fires and everything going on,” the exes “have found themselves leaning on each other more than ever,” the insider said.

The source explains that Miller “doesn’t feel threatened in terms of Jen ever getting back with Ben, but at the same time it’s hard not to feel jealous when it’s clear they have a strong connection and friendship.” BACKGRID Garner and Affleck were married for 10 years, from 2005 until 2015. Thecelebrityfinder/MEGA They coparent their three children: Violet, Seraphina, and Samuel. MEGA

Last month, the “Alias” star invited the “Good Will Hunting” actor to celebrate Christmas as a family with her and their three children. 

They also spent Thanksgiving together as the former couple helped feed 2,000 homeless and near-homeless people in downtown Los Angeles before dining together as a family later that day.

“Ben and Jen’s kids are really enjoying spending the holidays and family time together,” our source explained. “It’s a really great cohesive unit.”

Reps for Miller, Affleck, and Garner did not immediately respond to Page Six’s requests for comment.