The typewriter

A husband and wife decided they needed to use "code" to indicate that they
wanted to have sex without letting their children in on it. They decided on the
word Typewriter. One day the husband told his five year old daughter, "Go tell
your mommy that daddy needs to type a letter". The child told her mother what
her dad said, and her mom responded, "Tell your daddy that he can't type a
letter right now cause there is a red ribbon in the typewriter." The child went
back to tell her father what mommy said. A few days later the mom told the
daughter, "Tell daddy that he can type that letter now." The child told her
father, returned to her mother and announced, "Daddy said never mind with the
typewriter, he already wrote the letter by hand."