Short Story Brainstorming

Initial setting: grocery store, 1950’s. Mom with young son.. maybe 8 years old, and twin babies.  Tells son to wait in front of the store with the groceries while she goes to the car with the babies to pull it up in front of the store. She goes. Son waits and waits and waits. The mother forgot him.  Boy realizes. Decides he does not want to go home right away, just to help watch the babies.  But he can’t leave the groceries.  Takes the cart with him all over town in his adventure. What does he do?  Gets ice cream, takes himself to the zoo, tries to find his dad’s office… what is the mom doing this whole time? Goes home. Puts the babies down for a nap. Puts her hair in rollers and watches her soaps.  Realizes Johnny(?) is missing when she goes to make dinner for her husband, and none of the ingredients she bought are there.  Is this a big city or small town? Suburb?  Where does the father work?  Is the mother empty-headed, or was it a simple mistake, a one-time occurrence?