An old classic:

Dr. Irwin Bupkin was the pride and joy of his hometown of Summit, New Jersey. He became such a brilliant cardiologist he wrote the definitive paper on heart disease. His hometown of Summit invited him to read it in the city auditorium at their annual medical fundraising gala. The whole town was there for the black tie event.

Dr. Bupkin walked up to the dais to wild applause and put his paper on the lectern and adjusted the microphone. The microphone slipped down and knocked his papers off. Bupkin turned to pick up the paper and the microphone was right on his butt. When Bupkin bent over to pick the papers from the floor, out came the most unfortunate and loud and longest fart ever emitted and it was amplified by the microphone and blasted over the auditorium speakers.

In shock and horror, Bupkin picked up his papers and ran out the back door to his car vowing never to return to his hometown of Summit ever again.

Many years later, unfortunately, Bupkin’s mother became ill and he came back to town and checked into the Hyatt at midnight in the cover of darkness under the name Cohen.

As Bupkin was checking in, the friendly young hotel clerk asked;

“Welcome, Dr. Cohen, have you been to Summit before?”

“Yes,” said Bupkin, “actually I grew up here, but I haven’t been back due to an embarrassing incident that happened years ago.”

“Well, Sir,” said the helpful clerk, “it’s been my experience that what people think was an embarrassing incident usually wasn’t even noticed in the first place. And, besides, if it has been years, like you said, if they did notice, I am sure they’ve forgotten all about it, whatever it was.”

“You know, you may be right,” said Bupkin.

“How long ago did it happen?” asked the Hotel clerk.

“A while now.” said Bupkin.

“Well,” the clerk asked, “was it before the Bupkin fart or after?”