According to the screenwriter of The Imitation Game:
"Fleming's job was to come up with preposterous spy stories, that weren't real, but would be believable to the Germans," he said, referring to the spycraft necessitated by Turing and team's breaking of the German codes.
"Turing thought that Fleming's plots were just ridiculous . . . . He kept rejecting Fleming's plans, and so Fleming got really irritated with him."