We went to dinner with another couple tonight and towards the end of our meal we began to smell something really funky. At first we thought it was garbage from the busser station not far from our table -- yes it was that foul we thought it was garbage -- but after we mentioned something and they cleared the station the smell was still there.
A waitress came over and explained that it was an ingredient in the food on the next table and we couldn't believe it. It was so bad that we skipped dessert and left the table. We paid standing at the hostess' desk.
When choosing the items for your menu ask if something has a strong odor and see if there are some alternatives. You don't want your guests leaving early because something is making them nauseous.
I know this is kind of random but I never would believe that at a high-end restaurant we would have to leave early because of a horrible smell and thought it could happen at a wedding.