Why do victor and his friends start making fun of Joey in tangerine

Victor and his friends made fun of joey because he become close to Paul who they referred to as the Fisher man.

Explanation:

Paul was a student of the Tangarine middle school, he joins the school soccer team without informing anyone that he is visually handicapped. As a result of his condition Victor resulted to bullying Paul.

Towards the end of a football practice Victor and his friends asks Joey why he is always with Paul, he encouraged him to stay away from Paul which was very difficult for Joey to do. Victor and his friends ended up giving Joey a new name "Charlie the Tuna"