A seemingly innocent embrace between exes Ben Affleck and Jennifer Garner at their son’s birthday party has stirred more than just nostalgia—it may have triggered serious tension behind the scenes. According to a source close to the couple, Garner’s current partner, businessman John Miller, was “noticeably upset” by the affectionate gesture and has reportedly issued an ultimatum.

The video in question surfaced last month during a paintball-themed birthday celebration for Samuel, the 12-year-old son of Affleck and Garner. In the footage, Affleck was seen warmly wrapping his arms around Garner in what appeared to be a moment of casual intimacy between co-parents. While fans on social media immediately began speculating about a possible romantic reconciliation, others, including those closest to the situation, interpreted it quite differently.

“It Crossed a Line,” Source Claims

According to reporting by Page Six, John Miller—a longtime on-and-off partner of Garner—was not pleased by the nature of the hug, especially given its public visibility and subsequent speculation.

“John knows nothing inappropriate is going on,” an insider shared, “but he thought the photos and video were not respectful to his relationship with Jen.”

The source elaborated that Miller had always been supportive of the co-parenting dynamic between Garner and Affleck but believed this instance “crossed a boundary.” It reportedly wasn’t the first time Miller had felt uneasy about their closeness, but this latest event prompted him to confront Garner directly.

“He gave her an ultimatum,” the insider claimed. “He doesn’t want to see anything like that again, or he feels he has no choice but to walk away.”

Longstanding Tensions Over Garner’s Ties With Affleck

This isn’t the first time Miller’s discomfort with Garner’s ongoing connection to Affleck has made headlines. Back in February, Page Six also reported that Miller had expressed concerns about how much time the former spouses were spending together.

“John has always understood that Ben and Jen have to co-parent,” a source noted at the time. “But lately, it feels like the dynamic has grown deeper—holidays together, family trips, private talks.”

Miller reportedly felt that the relationship was evolving beyond parenting duties, especially after Affleck began spending major holidays such as Christmas and Thanksgiving with Garner and the kids. While there’s no suggestion of a rekindled romance, the closeness has raised eyebrows.

“Originally, it was about the kids,” the source added. “But now John feels like it may be about more than just parenting.”

The Garner-Affleck Dynamic: A Complicated Bond

Jennifer Garner and Ben Affleck finalized their divorce in 2018 after 13 years of marriage. Since then, the pair have maintained a notably amicable relationship, co-parenting their three children and often appearing together at public family events.

Garner is widely credited with helping Affleck navigate difficult periods, including his struggles with addiction and, most recently, his much-publicized breakup with Jennifer Lopez. In fact, Garner’s behind-the-scenes role during Affleck’s marital difficulties with Lopez raised further speculation that she had become something of a “marriage counselor” to the estranged couple.

Friends close to the situation have reportedly expressed concern that Garner is being pulled too deeply into Affleck’s personal life, sometimes acting as a stabilizing figure during moments of turmoil.

“She’s always been supportive,” said one source. “But there’s a difference between helping someone and becoming the default emotional crutch.”

Where Things Stand Now

Neither Garner nor Miller has commented publicly on the alleged ultimatum. However, insiders suggest that Garner values Miller’s honesty and is taking his feelings seriously.

Still, with Affleck’s presence firmly rooted in both her life and that of her children, navigating boundaries could prove challenging. For now, the trio remains entangled in a public balancing act—one that has fans and media outlets watching closely.

As of late, Affleck himself has remained largely silent, declining to speak on either his relationship with Garner or his split from Jennifer Lopez. He has, however, been seen spending more time with Garner and their children, further fueling speculation about their bond.

Conclusion: A Love Triangle Without the Romance?

While there’s no concrete evidence of rekindled feelings between Ben Affleck and Jennifer Garner, the optics of their public interactions have clearly rattled the dynamic Garner shares with John Miller. Whether the alleged ultimatum leads to change—or even separation—remains to be seen.

What’s clear is that for Garner, balancing the roles of co-parent, confidante, and committed partner may be getting increasingly complicated, especially under the lens of public scrutiny.