amir and hassans friendship is not a master/servant but a friendship one.

The way i see it, Amir and Hassan are more like friends than master/servant. This can be seen when the two form a kite cutting team enabling them to win the tournament(P.g. 66), or when assef harasses them, but hassan pulls out a sling shot, while amir is trying to talk to him. However, Amir can't help but feel envious of hassan. These is because in his point of view, hassan gets everything that amir wants, like babas attention. For instance, when baba hires a surgeon to fix hassan's lip scar, amir says, "I wish i too had some kind of scar that would beget baba's sympathy". (pg. 46) This makes amir act a little bit mean towards hassan by teasing him. This feeling seems to be so deep, that he searches for hassan after hassan runs for the kite that might finally win baba's approval.

Even though Amir is jealous of hassan, we can see that he still considers him as friend. For instance Amir bites his fist really hard that it starts to bleed(p.g 77), when he sees his friend, hassan getting hurt by assef, but he's to helpless to do anything about it. This shows that Hassan and amir's friendship is a true one, and not that of a master/servant.