Situational irony can be defined as something happening that takes both the reader and the characters involved by surprise, as everything seemed to be leading up to a different outcome. This can be seen in this short story by the ending, which is of course very different from the kind of ending we expect as the story progresses. After the renewed friendship and relationship between Sam and Sophy, the reader is led to believe, just as Sam is led to believe, that they will marry and enjoy a happy ending. However, it is the final paragraph that Hardy uses to reveal the somewhat bleaker version of events as they transpire:
The man, whose eyes were wet, held his hat in his hand as the vehicles moved by; while from the mourning coach a young smooth-shaven priest in a high waistcoat looked black as a cloud at the shop keeper standing there.
The true significance of the title is made known at this point, as only at the end of the story does the reader understand the true significance of "the son's veto": he has forbidden his mother to marry again, so strong is his aversion to anything that could threaten his own rise up the ranks of society. The ending is therefore an excellent example of situational irony precisely because it is something that Hardy, in his skill as a storyteller, does not lead the reader to suspect.