He's a half vampire, half human (Half-blood, dhampir etc). Based on the chapter it looks like his mom is human and his dad is vampire. To my understanding, there is a way to control his vampire hunger without the need to drink someone's blood where he is able to to take energy from people/humans instead (this was mentioned briefly in the beginning of the story, not in full detail though).
So his mother is teaching him that there is no need to feed like normal vampires do, that he can get what he needs from their energy. Apparently from this he is able to keep his human form from this. I do have many question that I hope will be answered at some point though. Like why does he have two forms, vampire and human form? Does it have to do with him being half-blood? I'd also like to know is the energy taking thing possible only b/c Ethan is a half-vampire or is it possible for all vampires but most prefer to take by feeding and taking blood.
Ok, now I'm a little confused. So, 24 years ago Ethan was a child?! So he's not an ancient vampire? Why did I think he was? And why is he so pale, when mom is so tanned? Does he take after his father? Dad must be the vampire, then. Mom is definitely giving me human vibes. If so, how and what is she teaching him about what I can only assume is "feeding"? Interesante! Hmmmm...