Why is he crying?

I read Flannery O'Connor's short story "The Geranium" over the weekend. It is one of her earliest published stories, dating to 1946, and opens a window into the mind and a little of the life of an elderly southern man who has been moved to NYC to live with one of his daughters.

In the pivotal scene of the story, the man - Old Dudley - is returning from a busywork errand his daughter has asked him to do. The ascent up the tenement stairs reminds him of a hunting trip he took once, and he is caught play-acting at hunting by a well-dressed black man whom he has previously thought of insultingly. The well-dressed man is polite and friendly, and helps him back up the stairs, which Dudley is obviously struggling with, chatting about guns and hunting.

Once having delivered him back to the tenement rooms , Flannery writes of Dudley, "The pain in his throat was all over his face now, leaking out his eyes."

Is he crying because - as he thinks to himself - he is "...trapped in this place where niggers could call you 'old-timer'." ? Or is he crying because the sudden and unexpected kindess and companionship and kindness of a stranger unleashes his longing for his home in the south? Or is it some combination of the two - that the homelike conversation is coming from a person who Dudley's social values do not allow him to respect?

Either way you read it, 'The Geranium' is a penetrating story.