11 O'Clock News
A blonde and a brunette were watching the 11 o'clock news. The current news story was about a man up on a ledge who was threatening to jump. The station cut to a commercial.
Brunette: "I bet you $20 he's going to jump."
Blonde: "OK."
(back to newscast)
He jumps.
Blonde: "OK, Here's my $20."
Brunette: "No, that was too easy. I can't take it."
Blonde: "I insist. I lost."
Brunette: "I have a confession to make. I saw the same thing on the 6 o'clock news and knew he jumped. So it wasn't really a good bet."
Blonde: "I know. I saw the same newscast. But I didn't think he would be stupid enough to jump twice."