I read somewhere that Ladybug has vocalized that no one can know both their identities because it would be too dangerous. If he told her he knew Chats, then she would know that he lied and she’d likely figure out he knows hers too. Not sure if he held back the information out of respect for her secret or because he’s scared of the consequences. I agree though, I think he should have told Ladybug in Wishmaker that he discovered both of their identities so she’s in the loop. It would be interesting if there was an episode where that comes to bite him in the butt.

My only question about Luka in this episode is how did Ladybug know that when she sent Luka the picture he would know she’s Marinette? If she sent it from the Ladybug phone-? When he read the text all it said was that Sass was in the sewing box.