In a well developed paragraph of 5 - 7 sentences, describe the situational irony in "The Gift of the Magi". How is this irony critical to the story's theme?

The situational irony is the basis of this short story's plot. The poor spouses, Della and Jim, have only two things of value, and no money to buy Christmas presents for each other. Their lives are dismal, so they really want to bring some joy to each other, at least on Christmas. The only thing Della can do to buy a watch chain for Jim is to sell her hair. The only thing Jim has in his possession is that same watch. At the end of the day, Jim comes to realize that she doesn't have the hair to put the combs on, and she understands that he doesn't have the watch anymore. The irony is critical to the theme because they realize that their love is, ultimately, the only thing they really have.