I once told this story to a female co-worker. It always works better on the ladies.
"You would not believe what I just saw. I stopped by a service station to visit a friend who works there. We were standing outside talking when a guy walks up with a bucket. (this was a long time ago) He fills the open bucket with gas and walks over to pay for it, saying he had run out of gas and did not have a gas can, just the bucket. Meanwhile a stray dog walks up and starts drinking from the bucket. In a moment, the dog starts hollering and running around the gas pumps in circles. Then he just fell over. (timing is everything here, know when to be quiet.)"
My co-worker thought a moment and with great concern asked, "was he dead?"
"No, he just ran out of gas."
She chased me down the hall with a coke bottle.