Just a little joke i heard.
               a husband and wife decide they need a way to let eachother know when they want to have
               sex without letting their kids in on it.  So they decide on the code word "typewriter". 
               One day the husband says to his 5 year old daughter, "Go tell mommy that daddy wants to
               use the typewriter."  The daughter gives her mom the message, and the mom replies
               "Please tell your dad he cant type right now because theres a red ribbon in the typewriter
               and the letter would come out red."  A couple of days later, the mom tells the daughter to
               to relay a message to her father: "Tell daddy he can come and use the typewriter now"
               The girl talks to her father, then returns with yet another message: "Daddy said never mind
               the typewriter; he already wrote the letter by hand.