What does "Sing it, sister" mean? “Catey, listen to me. I love Mills and Billy, and we totally bonded while we were making the movie, but you have to understand something about both of them—they’re actors.” Everyone in the room said “Uh-huh” and Kenz added, “Sing it, sister.” “Of course they’re actors,” I said. “That’s why they’re in the movie.”