"I introduced my two girls to Taylor Swift," Affleck tells ET's Carly Steel while promoting his new movie, The Accountant. "It was like God came down and walked on water. They didn't say a thing. They were totally frozen."
ET took Affleck back to his own childhood days by showing him a 1984 clip of himself as a pre-teen in the educational series, The Voyage of the Mimi. Affleck admits that his children haven't seen his early work, but not for lack of interest.
"I don't talk much about being a child actor because I don't want them to get any ideas about doing it themselves," he explains.
As a father of three children (Violet, 10, Seraphina, 7, and Samuel, 4), Affleck's kids are the most important part of his life, which is a far cry from the loner character he plays in The Accountant.
In the chilling crime thriller, Affleck stars as freelance accountant Christian Wolff, who has more affinity for numbers than people. Behind the cover of a small-town CPA office, Wolff cooks and uncooks the books for some of the world's most dangerous criminal organizations, but when the Treasury Department's Crime Enforcement Division, run by Ray King (J.K. Simmons), starts to close in on him, the body count starts to rise.
"The real fun actually was training for fight scenes and the physicality of it," Affleck says. "I was really dedicated to make the action as good, as realistic and with as much me as possible."