Abstract: A straw for a drinking container that is self-ventilating and self-sealing. The straw has two parts, a straw tip and a straw cover. The cover is retained on the straw tip and is movable by manual pressure between a closed position and an open position. The tip has a solid closed top and an open bottom to allow for a straw extension piece to extend into the container for drawing liquid up into the straw. The straw is self-sealing in that a hole in the cover through which a user would suck is sized to sealingly fit the end of the tip in the closed position. In addition, the cover and tip are sealed at the open bottom in the closed position and drainage holes in the tip allow any liquid that falls between the cover and the tip to flow back into the container. The tip has an abutment surface around its perimeter between holes that release liquid in the user's mouth and holes that allow for air intake.