I don't think he "knows"? But then, it's too early. It's good that he's dependent on DG.
From there, an unavoidable bond is formed. His feelings just have to grow from that point on. Of course, he won't acknowledge it, so he does everything that screams,"don't get the wrong idea, I don't like you" to the main character and the readers... and while it DOES look like that, even to me, the jealousy from recent chapters is sort of undeniable truth.
The feeling of possession is already a gateway. Still... it's a little too early for him to realize. It's probably good if he does, but I kinda want his feelings to grow first and h to begin unconsciously being nicer... realizing his feelings and being all defensive and keeping them a secret is good, too. When a person who's yet to fall in love does...
Especially if they're the arrogant type and the person they like happens to be the type they don't like or don't seem to like... it suddenly becomes more interesting.
You're so
Fucking
Precious
When you
Act like you don't know that you're in love with him