The Riddle of Sex

"Look here Darling....in this picture she doesn't have one....I'm pretty sure we're both not supposed to have one!!!!"
"Oh Fred.....who are you going to believe....me or some dusty old book?"
"Of course Dear....I always believe you....it's just that....well...none of my friends seem to have sore throats and aching jaws after a date with their girls...."
"Love hurts sometimes Fred....now why don't you get down on your knees and show me again how much you love me!!!!"