The girls had reached the meat counter and were asking McMahon something. He pointed, they pointed, and they shuffled out of sight behind a pyramid of Diet Delight peaches. All that was left for us to see was old McMahon patting his mouth and looking after them sizing up their joints. Poor kids, I began to feel sorry for them, they couldn't help it. I look around for my girls, but they're gone, of course. There wasn't anybody but some young married screaming with her children about some candy they didn't get by the door of a powder-blue Falcon station wagon.

On the other hand it is possible that Sammy could have been just a smitten with the three girls boyfriends or not, but through the context it seems like he would not have been as apt to stare at them the whole time; he might have perhaps glanced occasionally. In addition, he never would have quit if they had boyfriend with them. When Sammy quit he was trying to make sure that the three girls heard him, and hoped that they saw what he was doing. Sammy wanted it to appear as if he was defending...

No, if they were homely looking his initial fascination would not have been there, therefore he would not have felt the need to be their savior. On the other hand if they were with their boyfriends he may have still had that physical attraction or fascination, but he would not have tried to be the hero in front of their boyfriends. Sammy would still have his job, having the same plain Thursday afternoons.
The store's pretty empty, it being Thursday afternoon, so there was nothing much to do except lean on the register and wait for the girls to show up again.

Work Cited

Updike, J. (1961). A&P. In Pigeon Feathers and Other stories. Retrieved from www.tiger-town.com/whatnot/updike