The gesture gains significance in Brophy's novel when his young protagonist, an extreme romantic idealist, is scandalized by seeing his sweetheart innocently use it in conversation with some hospitalized soldiers, who smirk knowingly at her and each other.

Brophy was just that sort of idealist. Lying about his age, he managed to enlist in the British Army bfore he was 15 [!] and grew disillusioned on almost the first day. He served four years in the infantry on the Western Front.

His WW2 novel, "The Immortal Sergeant" (1942) was made into a movie starring Henry Fonda.

Possibly his biggest literary success was "Gentleman of Straford" (1939), a fictionalized life of Shakespeare.