I realized a while ago he's never told anyone he likes her. The only people that have found out Adrien has a crush on Ladybug, or got any hint that he might like her were Lila (when she was in his room and looking through his stuff and found pictures), and Felix from what we can see in the trailer.

Chat Noir has no problem telling anyone he loves Ladybug. Marinette has told at least Alya she likes Adrien, and her other friends were either told or figured it out because of how obvious she is.

So it seems odd that Adrien's kept it a secret from everyone, including his few friends.

Is it possible he thinks his identity could be found out if LadyNoir were to happen? Or does he think he has no chance with her if he isn't a superhero? (Which would explain him being more flirty with her when he was Aspik).