Most of the plot of this story occurs in "the past." The speaker has died and is going to be judged by God -- judged for his actions. While there, he is asked by an angel if he belongs to a certain group of men waiting to be judged. At that point, we flash back to the life of someone named Dulcie.
She is a poor girl who works for $6 per week (a long time ago). That is very little money and she is often hungry. She has been asked on a date by a fairly rich guy (Piggy). It seems that he dates poor girls. What is implied is that he gives them food and such and expects them to sleep with him
Dulcie refuses at the last minute to go out with him. But the narrator tells us that at some later time when she is hungrier, she does go out with him.
Then we return to the afterlife. The group of men the angel had asked about were men who owned the places that girls like Dulcie worked -- the men who paid them so little they had to sleep with men to get food,
The speaker says he burned down orphanages and killed a blind man -- but he was not as bad as the men who paid the girls so little.