I came across the word “non-affair” in Jeffery Archer’s novel Kane and Abel, which I just finished reading yesterday. The word appears in the following sentence (p. 544):
“She couldn’t recall another occasion when she was so aware of a first kiss. When he left her in the shadows of Fifty-Seventh Street, she realized that this time he had not mentioned tomorrow. She felt slightly wistful about the whole non-affair.”
I took 'non-affair' simply as the absence of any positive actions / events, and thought the word should be in every dictionary. But, curiously enough, Oxford, Cambridge, and Merriam-Webster don't include “non-affair” as a headword despite its casual look, though they include several dozens of “non+noun” compounds ranging from 'non-aggression,' 'non-appearance,' 'non-event' to 'non-stop,''non-violent,' and 'non-white.'
Google's NGram Viewer neither show any instances of 'non-affair.'
Is “non-affair” a well-used English word, or just a coinage by the author?