ET spoke with the 45-year-old actor on Monday night in Los Angeles at the big event, where he walked the red carpet without girlfriend Lindsay Shookus. Affleck said he wanted to keep the spotlight on him and his fellow co-stars, including Ezra Miller (The Flash), Gal Gadot (Wonder Woman), Jason Momoa (Aquaman), Ray Fisher (Cyborg) and Henry Cavill (Superman).
"I'm afraid I'm solo tonight, but tonight's all about the team -- the group, the Justice League -- and the movie, and I'm just so excited," Affleck told ET's Carly Steel. "We've been working on this movie for so long, so hard -- that it gets a release and the fans get to see it is really, really exciting."
Affleck also joked about his co-stars showing ET their go-to dance moves on the red carpet.
"Those are braver cast members than me," Affleck cracked. "This member keeps his go-to moves to himself. That's why I quit drinking -- because I don't want to be dancing like that anymore."
Later, the father of three was looking forward to keeping the vibe relaxing at the after-party.
"I just did Jimmy Kimmel's show and that was a lot of fun, and then there's a party after that I'll go to .. you know, just sitting down," Affleck shared about his plans for the rest of the night. "I've been doing a lot of talking."
As for how his own kids -- 11-year-old Violet, 8-year-Seraphina and 5-year-old Samuel -- will see Justice League, Affleck surprisingly told ET that he's planning to take them to the movies just like any other moviegoer.
"They haven't seen it," Affleck revealed. "This movie has only been really finished properly in the last few weeks and I'm gonna set up a screening... it's not a screening. I'll just take them to the theater at some point when my life gets a little less busy."
"That's sort of the way you should do it," he added about seeing the blockbuster film with an audience. "That's the really fun thing about these movies. The genre movie, the spectacle, you see it on the big screen because a lot of work went into making it seem big, you know?"