There’s a line in Hay Fever that reads “You can see Marlow on a clear day, so they tell me” but which Edith Evans, in rehearsals, read as “You can see Marlowe on a very clear day.” Correcting her, Coward said “No, dear, on a very clear day you can see Marlowe and Beaumont and Fletcher.”
Judy Campbell, who toured with Coward in the war, got annoyed with him.
Campbell: Oh, I could just throw something at you!”
Coward: Try starting with my lines.
And bringing it back to Blithe Spirit, and Fletcher (Jessica), Claudette Colbert was fluffing her lines.
Colbert: Oh, dear, I knew them backwards this morning.
Coward: And that’s just the way you’re delivering them, dear.