Lorraine's feelings for John change slightly through the novel. At the beginning of the story, it is clear that Lorraine thinks of John as a friend. She thinks he is an attractive friend, but there are no romantic feelings there. . . yet.
Because Lorraine is John's friend (one of his few actual friends), she cares about what happens to John. She wants to protect him. She mainly wants to protect him from himself too. John is a certifiable drunk, and he is a compulsive liar. Lorraine goes with him on a lot of schemes like the phone call game, but she most definitely tries to put the brakes on his scheme to have a party at Pignati's house.
Eventually, Lorraine's feelings for John begin turning toward romantic inclinations.
“John, stop it now. I’m not kidding.” She started laughing again right in my arms, but I stopped it by putting my lips on hers. It was the first time we had ever kissed. When I moved my lips away from hers, we just looked at each other, and somehow we were not acting anymore.
Their relationship doesn't move much beyond that initial kiss, because the story's conflict gets in the way.