Simple
This is how he defines relationships:
Liz: sister, family
Davie: nephew, family
Gil: friend, sponsor, ex-friend, traitor, enemy
Oakes: boss
Rosie Larson: first case
Jack: coworker's son, friend
Chief Jackson: enemy
Carlson: boss, enemy
Karl Reddick: coworker, mentor (sort of )
Caroline: work connection, girlfriend
Bullet: friend, self, traitor, friend, self
Sarah Linden: coworker, mentor, companion, friend, family, something, something, something
-End-