How do John and Lorraine become friends in Paul Zindel's The Pigman?

In chapter 2 of Paul Zindel's The Pigman, John and Lorraine notice each other at their bus stop. Lorraine explains that one day John had to sit next to her because there was nowhere else for him to sit. According to Lorraine, John just started laughing for no apparent reason while sitting by her. This embarrasses Lorraine because she thinks that John is laughing at her. As a result, Lorraine asks John to stop laughing and he responds by saying that he is a lunatic. Lorraine says, "Well, I wouldn't go around bragging about it" (15). By this point, Lorraine is feeling very paranoid when she drops her books on the floor. John keeps laughing and Lorraine ends up laughing, too, even though she feels insecure. In the end, both John and Lorraine bond as friends because they share a good laugh together.