Pygmalion was the most broadly appealing of all Shaw's plays. But popular audiences, looking for pleasant entertainment with big stars in a West End venue, wanted a "Happy ending" for the characters they liked so well, as did some critics. During the 1914 run, to Shaw's exasperation but not to his surprise, Tree sought to sweeten Shaw's ending to please himself and his record houses. Shaw returned for the 100th performance and watched Higgins, standing at the window, toss a bouquet down to Eliza. "My ending makes money; you ought to be grateful," protested Tree. "Your ending is damnable; you ought to be shot." Shaw remained sufficiently irritated to add a postscript essay, "'What Happened Afterwards," to the 1916 print edition for inclusion with subsequent editions, in which he explained precisely why it was impossible for the story to end with Higgins and Eliza getting married.
He continued to protect the play's and Eliza's integrity by protecting the last scene. For at least some performances during the 1920 revival, Shaw adjusted the ending in a way that underscored the Shavian message. In an undated note to Mrs. Campbell he wrote,
When Eliza emancipates herself – when Galatea comes to life – she must not relapse. She must retain her pride and triumph to the end. When Higgins takes your arm on 'consort battleship' you must instantly throw him off with implacable pride; and this is the note until the final 'Buy them yourself.' He will go out on the balcony to watch your departure; come back triumphantly into the room; exclaim 'Galatea!' (meaning that the statue has come to life at last); and – curtain. Thus he gets the last word; and you get it too.
(This ending, however, is not included in any print version of the play.)
Shaw fought against a Higgins-Eliza happy-end pairing as late as 1938. He sent the 1938 film version's producer, Gabriel Pascal, a concluding sequence which he felt offered a fair compromise: a tender farewell scene between Higgins and Eliza, followed by one showing Freddy and Eliza happy in their greengrocery-flower shop. Only at the sneak preview did he learn that Pascal had finessed the question of Eliza's future with a slightly ambiguous final scene in which Eliza returns to the house of a sadly musing Higgins and self-mockingly quotes her previous self announcing "I washed my face and hands before I come, I did".