What is the source and nature of the conflict for the protagonist, Sammy, in John Updike's short story, "A & P"?

Sammy has several conflicts that confront him in John
Updike's short story, "A & P." All of them (directly and indirectly) have to do
with the store manager, Mr. Lengel. Sammy seems none to happy with the strict regimen of
the store, and when Lengel chooses to embarrass the three girls who appear in his store
in bathing suits, Sammy chooses to quit. Sammy would probably have not made this
decision if the customers had been different, but he was trying to impress the girls by
making a chivalric act in their defense. When Lengel tells Sammy that he is making a
mistake (Lengel is a friend of Sammy's parents and has probably given him the job for
this reason), Sammy rings up a "No Sale" on his register and heads outside to look for
the girls. Sadly for Sammy, they have already left and never seemed to notice his
actions.