In this story, Sammy decides to take a bold stance in defense of some girls wearing improper attire who have entered the grocery store where he works. When his manager tells them to come with their "shoulders covered" the next time, they begin to blush. Sammy leaps to their defense, telling his manager that he is quitting.
Lengel tries to get Sammy to change his mind; he's a friend of Sammy's parents and knows that Sammy is making a mistake. This is one point in the story where we have a hint that Sammy knows how this is going to turn out:
"You'll feel this for the rest of your life," Lengel says, and I know that's true, too...
This line is ominous and indicates that Sammy already realizes that there isn't going to be a positive outcome for his momentary stance of honor on behalf of the girls, who are already gone. But he also feels it's "fatal" to begin a gesture like this and then not follow through with it.
In the final paragraph, there is another indication that Sammy knew all along that the girls would not be impressed enough by his actions to wait for him after watching his grandiose gesture. When he goes outside, Sammy immediately looks for them:
I look around for my girls, but they're gone, of course.
The "of course" added at the end indicates that things turned out exactly as Sammy expected. He never truly believed that he would have a meaningful impact on the girls through his gesture.