Ben Affleck looks down on Jennifer Garner's beau John Miller: Source

Ben Affleck is seemingly upset that Jennifer Garner, with whom he shares three kids, has chosen John Miller over him. 

According to the latest findings of RadarOnline.com, the actor believes that John Miller is "too boring" for his former wife.

"He's constantly asking, 'That guy? Really?'" tipped an insider noting that Ben is unable to accept the businessman's presence in Jennifer Garner's life. 

 "Ben still thinks he’s the main character in Jen's life despite her having moved on," claimed the source.

They went on to add that "Seeing her build a calm, normal life with someone who isn’t a celebrity — it drives him nuts."

"There's no drama, no red carpets and no headlines with John. Just… kids and books," they also added explaining why Ben thinks that Jennifer is living a dull life with John Miller. 

Nonetheless, the longtime pair have reportedly found solace in each other and are said to be "fully committed" to each other.

"Friends say the root of Ben's unease lies in seeing Garner with someone who deviates so starkly from his Hollywood lifestyle," the insider insisted.

"But she finds solace in John's grounded presence," they remarked in conclusion.