1. I found out why hawkmoth akumatizes people, he is too lazy to ask for the miraculous himself.
2. Adrein has a crush on marinette but he thinks she doesnt like him cause she allways suns away from him.
3. In season 4, the episode "strikeback" you can tell ladybug gained feelings for cat noir, at the end of the epsidode, ladybug is blushing.
this one is not a theroy but it is a hidden easter egg,
4. in the back ok adrein's room, he has pictures of him and marinette kissing, going on dates, and even hanging out. this shows that adrein is secretly dating marinette.