You might want to refer to Chapter Eleven in this great novel, which is when John and Lorraine take advantage of Mr. Pignati's stay in hospital to dress up and have a meal together in his house. John puts on a suit and Lorraine looks through Mr. Pignati's wife's dresses to find something to wear. When she finally comes down, John splutters out, "You look beautiful!" As they joke around, he pushes Lorraine onto a bed and then kisses her. Note how John himself describes this incident:
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.
Even though this chapter is told from John's perspective, it is clear that his actions would have given Lorraine a very clear indication that John liked her and that their relationship was developing from a friendship into something more interesting.