Bob walked into a sports bar around 9:58 PM. He sat down next to a blonde at the bar and stared up at the TV.  

The 10 PM news was coming on. The news crew was covering the story of a man on the ledge of a large building preparing to jump. 

The blonde looked at Bob and said, "Do you think he'll jump?" 

Bob said, "Yeah, I bet he'll jump." 

The blonde replied, "Well, I bet he won't." 

Bob placed a $20 bill on the bar and said, "You're on!" 

Just as the blonde placed her money on the bar, the guy on the ledge did a swan dive off the building, falling to his death. 

The blonde was very upset, but willingly handed her $20 to Bob. "Fair's fair. Here's your money." 

Bob replied, "I can't take your money. I saw this earlier on the 5 PM news, so I knew he would jump." 

The blonde replied, "I did, too, but I didn't think he'd do it again."

Bob took the money.