FLY IN THE OINTMENT • FREE-TRANSLATOR.COM • Definition of Fly in the ointment

... Harold any more; she had lost faith in his ability as a musician. But she was disappointed that her charms were not sufficient to blind him to all others. That was the fly in the ointment. It was an affront to her beauty, and she was still beautiful. She was unctuously full-bodied, not quite so tall as Aileen, not really as large, but rounder and plumper, softer and more seductive. Physically she was not well set up, so vigorous; ...

— The Titan • Theodore Dreiser

... people sometimes said that she ought to have been a man. But she was quite happy as a woman, looking after her poultry and her garden out of doors, and her dogs and her household within. She had hardly moved from Mountfield since her marriage thirty years before, and the only fly in the ointment of content in which she had embalmed herself was that she would have to leave it when Jim married. But she greeted Cicely, who was expected to supplant her, with bright cordiality, and lifted up a loud voice to summon a groom to lead off Kitty ...

— The Squire's Daughter - Being the First Book in the Chronicles of the Clintons • Archibald Marshall