A college professor had just finished explaining an important
 research project to his class. He emphasized that this paper was
 an absolute requirement for passing his class, and there would be
 only two acceptable excuses for being late. Those were a medically
 certifiable illness or a death in the student's immediate family.
 
 A wisecracking student in the back of the classroom waved his hand
 and spoke up "But what about extreme sexual exhaustion,
 professor?" As you would expect, the class exploded in laughter.
 
 When the students finally settled down, the professor gave the
 student a long, appraising look. "Well", he responded, "I guess
 you'll just have to write with your other hand"