Ben Affleck turned 44 on AUG. 15 and to celebrate the Batman v Superman: Dawn of Justice star reunited with his estranged wife, actress Jennifer Garner, and their children, daughter Violet, 10, and Seraphina, 7, and son Samuel, 4.
"The family spent the week together at a Montana resort where they own a condo and enjoyed outdoor activities like hiking, biking and swimming," a source close to the couple exclusively tells Who.
"Ben is happiest when he's spending time with his family," adds the source. "It was a great birthday."
While Affleck and Garner separated in June 2015 after a decade-long marriage, they have kept a friendly relationship for the sake of their children. They continue to spend quality family time together, including a month-long trip to Europe earlier this year while Affleck was filming Justice League in London.