John, Norton, and Dennis usually go to the cemetery to drink beer together at "Masterson's Tomb." John says that he likes cemeteries because they are so well kept. For example, the lawns are green and the flowers are kept fresh. He likes the cleanliness of the cemetery so much that he says that the dead get nicer lawns and flowers than when they were alive.
As far as Norton is concerned, he shows up at John and Lorraine's party to scope the place out for things he can steal. Not only is he jealous that John and Lorraine have been spending a lot of time with Mr. Pignati without him, but his habit for stealing is getting worse and worse. It started out with him stealing marshmallows, and grew into something more criminal.
In chapter nine, Norton specifically meets John at Masterson's Tomb for a drink. His agenda, though, is to get John to tell him what tools, TVs, or radios Mr. Pignati might have that are worth stealing. When John won't tell him anything to help him, Norton threatens to "visit" the old man with Dennis on his own sometime. John doesn't give him a reaction, but Norton certainly does visit Mr. Pignati's house eventually. Out of spite and bad character, Norton visits on the night of their party to steal what he can and ends up trashing the place.