Abstract: A universal cap and straw drinking system is provided having a cap portion that is designed to thread onto an existing and readily-available drinking vessel. The cap portion has a first hole that interference fits to a flexible tube and prevents the tube from being slid relative to the cap portion. The cap portion has a second hole that is adjacent to the first hole and allows make-up air to enter the drinking vessel to make up for liquid being removed from the vessel through the flexible tube. The tube has a reinforced tip area where the wall thickness of the tube is doubled to increase the rigidity of the tube and reduce the ability of the user to pinch off the tube.