The man with no manners. Chewing with his mouth open, putting his elbows on the table, picking his teeth with a toothpick, or reaching over your plate, is gross. An inability to say "please" or "thank you" or being rude to waitstaff is even grosser. Discovering that he's rude to your friends or family is grosser than gross. In fact, it's grounds to run away, far far away. Manners are important. If a man never learned them, you don't want to take on the task of teaching him.