The present invention relates to a drinking apparatus including a vent system that removably connects to a drinking container. The vent system is used to create a variety of leak resistant drinking containers, such as toddler drinking cups, baby bottles, and other drinking containers. The vent system includes a substantially rigid disc portion and base portion, the base portion including base air vent channels merging into an integral one-way valve. The vent system provides passage for air from the exterior of the bottle to the interior of the bottle, but it does not allow liquid to exit the bottle via the vent system. An optional anti-bubble tube may be used with the vent system to provide for air entering the inverted container to reach an air pocket formed in the bottom portion of the container.