In future chapters
Spoiler!
Arun decided to turn human after a talk with his mother, so he can meet Isabella properly and so he became the 'son' of Rovina the Grand Duke. At first when Arun joined the palace he kept trying to remind himself to act like he remembers nothing that he isn't honey badger anfld the honey badger is dead and he is Arun now who is a knight apprentice that has never met Isabella and that he should try to befriend her now.
This is because when he chose to turn human and come to the palace as Rovina's 'hidden' son he's supposed to have no memories from when he was a dragon or honey badger but he does remember everything and acts like he doesn't. He does his best to get close to Isabella and he even once told her she was his first love which confused her and she asked if he met her before and things turned confusing and so his words were turned into a joke. Isabella felt her heart beat fast from the first moment but as usual she ignores it. Her father dislikes Arun and calls him thief and tries to get her away from and make her dislike him but it doesn't work.
I like to post spoilers for the stories I find interesting because I don't have much time to read novel due to busy schedule
you will find me in most romantic historical manhwa comment sections 
you will find me in most romantic historical manhwa comment sections 