The "Gone Girl" star, who recently confirmed his split from estranged wife Jennifer Garner, is the "happiest" when he is with his children, reported People magazine.
"He's happiest when he's with his family," a source close to the actor said.
Affleck was seen out with the kids as they headed to visit the Imagine It! Children's Museum.
They decided to visit city's Fernbank Science Center, after finding it closed.