A bottle assembly is provided. The bottle assembly comprises a bottle having an end portion including a first detent formation, and a collar having a second complementary detent formation. The collar is arranged to snap fit to the end portion by engagement of the detent formations by application of force only in a direction towards the bottle. In addition, a valve assembly for use with a drinking vessel is provided. The valve assembly comprises a base member and a sealing member. The sealing member is moveable, dependent on a pressure difference across it, between a sealed position, wherein the sealing member is sealed against the base member, and an unsealed position, wherein the sealing member is unsealed from the base member. One or more channels are formed between the base member and the sealing member and extend to a periphery of the sealing member. The one or more channels are arranged to allow air to enter the drinking vessel from the periphery of the sealing member when the sealing member is in the unsealed position.
