The "Batman v Superman: Dawn of Justice" star was thrilled to see his younger sibling Casey take home the gong for Best Performance by an Actor in a Motion Picture - Drama for his performance in "Manchester by the Sea" at the event on Sunday, reported Contactmusic.
"I was more nervous for him than I ever have been for myself. My kids stayed up to watch it. I went home today and I asked my four-year-old, 'Sam, did you see Uncle Casey up there? Did you see what happened?' And he said, 'The man said Casey Affleck!'," he said.