Bubba went to the doctor's office to ask for a          double dose of Viagra.  
The doctor told him that he couldn't allow          him a double dose.  
"Why not?" asked Bubba..  
"Because it's          not safe," replied the doctor.  
"But I need it really bad," said          Bubba.  
"Well, why do you need it so badly?" asked the          doctor.  
Bubba answered, "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 see? I gotta 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 morning, Bubba dragged himself in to          the doctor's office, his right arm in a sling.  
The doctor asked,          "What happened to you?"  
Bubba said, "Nobody showed up!"