when does chloe find out about lucifer

Chloe finds out about Lucifer's true identity, that he is the Devil, in episode 24 of season 3, titled "A Devil of My Word." This revelation happens after an intense confrontation with Lieutenant Marcus Pierce (who is actually Cain). During the shootout, Lucifer protects Chloe using his angel wings and flies her to safety. When Chloe regains consciousness, she sees Lucifer's devil face for the first time, confirming the truth of his identity. Initially, Chloe is scared of him after this discovery, which significantly changes their relationship dynamic moving forward into season 4 and beyond.