Ben Affleck ‘Having a Tough Time’ With Ex Jennifer Garner Planning Wedding to John Miller (Exclusive)

Jennifer Garner is preparing to walk down the aisle once again — and it’s causing her ex-husband Ben Affleck to spiral, a source tells Globe.

The actress, 53, has been involved in an on-again, off-again relationship with John Miller since 2018, but the pair are finally ready to make things official.

“It’s open knowledge among her friends [that] she’s knee deep in wedding planning,” the source tells Globe. “She’s looking into the perfect venue, the invitations she wants to send out, the music [and] the guest list.”

Though she’s maintained a healthy coparenting relationship with Affleck — who she shares three kids with — it seems the news has hit the Accountant 2 star, 53, hard.

“He was clinging to the hope she’d have second thoughts and call it off, but now that’s clearly not happening,” says the source. “He has to get his head around the fact she’ll be officially wed and tied down to someone else who’s going to be living under the same roof and spending time with his kids.”

As Globe readers know, Miller made sure that Garner left Affleck’s name off of the guest list for their nuptials, as a source said the businessman was “livid” after photos of the Academy Award winner hugging the Alias alum at a paintball park made their rounds in March.

Garner and Affleck split in 2015, but they’ve remained on friendly terms as they coparent. In fact, when the Good Will Hunting star — who has been open about his battle with alcoholism — entered rehab in 2018, it was Garner who drove him.

Though Affleck is “having a tough time” anticipating Garner re-marrying, the Once Upon a Farm co-founder couldn’t be happier.

“Jen has been back and forth on whether to marry John for a while — now she’s telling friends it’s happening, how happy they both are and [that] John’s her soulmate,” adds the source.