Sometimes, Lewin likes to joke around that Rin is his strongest familiar. Then promptly gets his hat tugged down over his face. He lifts it again to find Rin looking pouty. 

On bad days, if Lewin happened to hit a nerve without knowing it, Rin will backhand him and usually go hide on the roof. He likes to curl up there to be sad and alone.

Because that's all he really is, right? Lewin doesn't love him. Rin's upbringing by him is just the result of orders.

Rin is to be a weapon and nothing else. He's scared that once he's strong enough and the Order decides they want to use him against his father, his life will be taken away from him.

No boyfriend, no friends, no more normal American teenager's life. No school dances or rallies or football games. No college life or Frat Parties or being a real Exorcist. No more dreams of running his own resteraunt that people will come to eat at from all over the world.

No more Living.

Ryuji has learned that he has to invade Rin's privacy sometimes and just distract him from his thoughts to keep him from sinking into a depression so heavy and deep that the half-demon can't even get out of bed.