19. Were You Raised in a Barn?
This is just plain bad manners. People who chew with their mouths open have a nice way of ruining the appetite of others around them, and it’s just a generally unpleasant experience. This also falls in the category of talking while chewing, as it has the same unpleasant side effect.
Just give it a second to finish and swallow; I assure you no one will mind waiting for just a few seconds longer. This is a gross habit none of us want to be around and is the most basic of table manners.