Ben Affleck Takes Sam to Disneyland for a Day of Father-Son Bonding

With Jennifer Garner working in Atlanta, the duo has "the best time" at the theme park

Ben Affleck is a big kid at heart.

With Jennifer Garner filming Simon vs. The Homo Sapiens Agenda alongside Josh Duhamel in Atlanta, Ben is on full-time daddy duty. So, on Wednesday, he decided to visit Disneyland with his son Sam Affleck, 5; daughters Violet Affleck, 11, and Seraphina Affleck, 8, were M.I.A.

As a source tells E! News, "Ben wanted to set up a special outing for the two of them."

Mission accomplished. According to an eyewitness, Ben and Sam were "very cute" while enjoying Dumbo the Flying Elephant, It's a Small World, Mad Tea Party and other attractions. And, at one point, the 44-year-old dad was seen wearing a Batman backpack when Sam grew tired of carrying it around. "Sam was having the best time and wanted to ride again and again."

Ben went all out to make it an unforgettable day for Sam. "They had a special VIP Disneyland chaperone who helped them get to the front of the line," the source says of the service, which grants guests priority access to more than 30 rides and programs. "It was a great day for them."

The outing came a week after Ben announced he'd completed treatment for alcohol addiction, something he's "dealt with in the past and will continue to confront." In a Facebook update, the two-time Oscar winner told his followers, "I want to live life to the fullest and be the best father I can be. I want my kids to know there is no shame in getting help when you need it, and to be a source of strength for anyone out there who needs help but is afraid to take the first step."

Though the actors announced their separation in June 2015, Ben thanked Jennifer for being by his side throughout his struggles. "I'm lucky to have the love of my family and friends, including my co-parent, Jen, who has supported me and cared for our kids as I've done the work I set out to do," Ben wrote. "This was the first of many steps being taken towards a positive recovery."

Now that the world knows his secret, the actor-turned-director feels a great sense of relief. Ben decided to share the news himself because he "didn't want to cycle through anything he had dealt with in the past," an insider said last week. "He's moving in a healthy, balanced direction."

"He didn't want to hide. He will continue to work on it. This was a step, but it's a progressive process. He's in a good place," the insider revealed to E! News exclusively. "He learned a lot while he was there. Everyone has a story and was open about it. That was meaningful to him."