Clerk's mistress (The Shape Shifter)
From Tardis Wiki, the free Doctor Who reference
A clerk who worked in an office and had a wife named Daphne also secretly had a mistress. One night she met with him at his workplace while he called Daphne to tell her that he would be working late again. They were secretly observed leaving together by Frobisher, who had been hired by Daphne to investigate him and had taken on the form of a telephone on the clerk's desk. (COMIC: The Shape Shifter)
