Mark and Sharon decide they don't want to discuss sex in front of their 4 
and 6 year old children, so they decide to talk in code. 

One day Mark is feeling a little bit turned on and says to Katie, "Tell 
your mother I would really like to type a letter." 

Katie runs off to find her mom. " Mommy, mommy", shouts Katie, "Daddy would 
like to type a letter." 

Sharon replies slightly sheepishly, "Katie, go and tell your daddy that he 
can't type a letter today as there is a red ribbon in the typewriter." 

Katie tears off to her father and says, " Daddy, daddy, mommy says you 
can't type a letter today as there is a red ribbon in the typewriter." 

A few days later Sharon remembers that Mark was a little bit keen on a bit 
of nookie and she called Katie, "Katie, tell your daddy that he can type 
that letter today." 

Katie went off to look for her father and told him, "Daddy, mommy says you 
can type the letter today." 

"Thats OK, Katie", Mark says, "You can tell your mother that I don't need 
the typewriter any more, I wrote the letter by hand."