A man went to the doctor's office to get a doubledose of Viagra. The doctor told him that he couldn't allow him a doubledose. "Why not?" asked the man.

 Because it's not safe," replied the doctor.
 "But I need it really bad," said the man.
 "Well, why do you need it so badly?" asked the doctor.
 

The man said, "My girlfriend is coming into town on Friday; my ex-wife will be here on Saturday; and my wife is coming home on Sunday.
 Can't you u see? I must have a double dose."

 The doctor finally relented saying, "Okay, I'll give  it to you,
 but you have to come in on Monday morning so that
I can check you to see if there are any side effects."

 On Monday, the man dragged himself in; his right am in a sling.
 The doctor asked, "What happened to you?"
 The man said, "No one showed up".