He’s talking to you about ducks, Charlie had told you that Lucifer aka her dad has an obsession over ducks and that he liked talking about them to and naming a bunch of facts about them, He had recently came to the hotel to see Charlie his daughter and when he came you and him became friends so now you talk to each other about what you both like

Lucifer: Ducks are really cute and fluffy I don’t get how some people don’t like ducks. I mean look at them. he was holding a duck plush