Ben Affleck Teases He Was 'a Little Taken Aback' That Brother Casey Didn't Thank Him in Golden Globes Speech

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It looks like Casey Affleck may owe his big brother an apology! The Manchester By the Sea star nabbed his first Golden Globe on Sunday night, but failed to thank a very important person during his acceptance speech – his famous brother, Ben Affleck.

Ben visited Jimmy Kimmel Live! on Monday night to call out his Casey for the faux pas.

WATCH: EXCLUSIVE: Casey Affleck Talks First Golden Globe Win, Jokes Brother Ben Displays His Awards ‘In His Window’

“Someone was omitted… I was a little taken aback,” he teased. “That’s not the kind of thing I would do. If it’s me, you know, I thank people.”

And Kimmel proved the Live By Night star’s point, showing a clip from his 1998 Oscar win for Good Will Hunting, in which pal Matt Damon mentioned Casey and Ben chimed in with his own praise.

“I needed that little push, but I did say 'My brother is brilliant.' Those words came out of my mouth,” Ben quipped. “We didn't hear anything like that last night. I mean [there was] the thing with Denzel [Washington], and the thing with Matt [Damon], he was Mr. Hollywood."

Ben went on to note that if Casey were to win the Oscar, it would be a historic moment.

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"It would actually, historically be the first time that brothers won [Oscars in separate categories] and not just that, this would be the first time someone would win an Oscar who didn't brush his teeth from ages 10 to 14,” he continued, throwing jabs at Casey. “It would be the very first time that someone would win who pulls his pants all the way down at the urinal. Most Oscar winners don't do that. [It would be] the first person to win who's scared of butterflies...This would be the very first person to win an Academy Award who once asked his brother if Back to the Future was a true story."

Casey had his own quips about Ben when he spoke with ET’s Kevin Frazier directly following his big win.

“He likes to show off his hardware,” Casey joked of Ben’s two Golden Globes and two Oscars. “I’m not that kind of guy. I discreetly put it away. He's got it like in his window. Some people put Christmas lights or a menorah and Ben lines up his hardware.”

WATCH: EXCLUSIVE: Ben Affleck Says Brother Casey's Golden Globes Win Was the 'Most Memorable Experience in My Life'

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All jokes aside, Ben was very sincere about Casey’s accomplishment while talking to ET’s Carly Steel at the premiere of his film Live By Night on Monday.

"The overwhelming sense I had last night, watching my brother win, and believing in him for so long and knowing how talented he is… it was the most memorable experience in my life," the actor said. "I'm thrilled. I wish him the best, but already what he's done is amazing."

For more from Ben, watch the clip below!

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