Brothers

One evening after a few rounds of beer, two brothers decided to settle a dispute by fighting, and it was understood that whoever wanted to quit should say "Enough."
The first brother, named Arnie, got his brother Petey down, and was hammering him unmercifully.
After while, Petey called out several times, "Enough!"
Arnie paid no attention, and kept on hitting him.
Finally, a bystander shouted, "Why don't you let him up? Didn't you hear him say that he's had enough?"
"I did," said Arnie, "but he's such a liar, you can't believe anything he says.