Why Ben Affleck 'Felt So Bad' For 'Devastated' Ex-Wife Jennifer Garner

Jennifer Garner and Ben Affleck may be big Hollywood stars, but to their only son Samuel, they are just not cool.

Affleck recently revealed that his ex-wife was "devastated" when their son didn't like her elaborate costume for his 7th birthday party last week. During a red carpet interview with Entertainment Tonight, Affleck shared details about the "How To Train Your Dragon"-themed party where Garner dressed up as viking warrior Astrid to get into the spirit of the festivities.

Affleck explained that even he was "shocked as anybody" when he saw Garner in full Astrid costume, complete with leather armor, fur boots, a matching shawl and blue face paint. "But then she said Sam was like, 'OK Mom. We already have an Astrid,'" the actor told reporter Nischelle Turner at the premiere of his latest movie, "Triple Frontier."

Affleck said he "didn't go to quite those extremes" when it came to costumes, but he did make sure to "participate in a very heavy viking themed 'How to Train Your Dragon' birthday extravaganza." He added that he "felt so bad" for Garner, who had been "devastated" when her costume didn't get their son's approval.

"[Jennifer] had gone to all these lengths to put on the costume," he said, adding, "We're just not that cool."

Last week, the "Alias" alum shared a photo of herself in the Astrid costume on Instagram, revealing in the caption that her son was unimpressed by her efforts.

But while Samuel may not have been happy with his mom dressing up, Garner's followers praised the actress for her costume and how much effort she put into it. The post has since received over 700,000 likes and thousands of comments as of this writing.

Aside from Samuel, Affleck and Garner share Violet, 13, and Seraphina, 10. The two were married for a decade before announcing their split in 2015 and jointly filing for divorce in 2017. The "Daredevil" co-stars finalized their divorce in October last year.

Garner has since moved on with Cali Group CEO John Miller, while Affleck has dated Lindsay Shookus and Playboy model Shauna Sexton.

Affleck and the "Saturday Night Live" producer broke up last year, shortly before he entered rehab, but the two were recently spotted hanging out again, Daily Mail reported.