Yawning in the presence of others is impolite. If the urge to yawn suddenly arises, rub your forehead in an upward stroke to suppress it. If this is not enough to restrain the yawn, use the tip of your tongue to lock your lips shut, and cover your gaping mouth with your hand or sleeve to conceal it from others. Sneezes should also be stifled. Sneezes and yawns make you look very silly. There are many other points of etiquette that you should be mindful of at all times.