The 44-year-old actor has already won three Golden Globes -- two for Argo
, and one for Good Will Hunting
-- and if his brother, Casey Affleck
, picks up a Best Actor in a Drama win for his performance in Manchester by the Sea
, the two will be the first brothers to ever win a pair of Golden Globes. So, does Ben think Casey will win?
"He can," Ben told ET's Carly Steel on Friday at the junket for his new film, Live by Night.
"I was trying to see if there were any brothers that have won Oscars for separate movies for separate categories in separate years, and I'm not sure there are. Warren Beatty and Shirley MacLaine both won, and they're siblings, but they're not brothers."
Either way, the Affleck brothers would be making history. "That's what I hope," Ben says.
Despite the stakes, Ben says his little brother is taking all the awards season pressure in stride.
"He's doing great, and handling it really well," the Oscar-winning actor shares. "It's a lot of pressure, rather, and a lot of stress, but you know, he's got a very solid constitution and a good head on his shoulders. You know, he's a grown man, so he's dealing with it well."
Ben is hoping to make a low-key appearance at the show this Sunday, after being the butt of one of Ricky Gervais' most brutal jokes
at the Golden Globes last year, when the British comedian called the father of three "unfaithful." Ben remains a good sport about it, and says it all comes with the territory of being a celebrity.
"I think Ricky Gervais was kind of famous for insulting people, making people uncomfortable," he says. "I think Tina [Fey] and Amy [Poehler] were great at kind of walking that line without being sort of super mean-spirited. I think [this year's host Jimmy Fallon] is more of the Tina and Amy school, you know what I mean? I think he'll make it really entertaining and, you know, I'm sure there won't be any shortage of good-natured zingers at people in the audience, which is part of the -- it's what you pay for when you show up."
"I'm getting a seat way in the back!" he jokes. "Like, I'm hiding!"
For now, Ben is busy getting back to work in the new year, after spending the holidays in Montana
with his family, as well as his best friend, Matt Damon, and brother Casey. But Friday also marks a special day for Ben, who's celebrating his daughter Seraphina's eighth birthday.
"We did a little birthday this morning, and she got a little pin at school," he shares about how Seraphina's special day has been going so far. "She's actually going away on a trip with her mom [Jennifer Garner] for a special birthday treat tonight, so she's doing good."
As for what Seraphina wanted this year for her birthday?
"We don't have enough time with birthday wish list," he jokes.
Ben directed, wrote and stars in Live by Night, and his good friend, Leonardo DiCaprio, is one of the producers.
"He came on set ... he was very supportive," Ben says of DiCaprio. "He's a smart guy and got to where he is because he really understands a lot about movies and I appreciated his support."
Watch the video below to see Ben's co-star, The Mindy Project
's Chris Messina, explain how he gained 40 pounds
for the film. Live by Night
is in theaters now.