A drinking vessel for a liquids packaging product. The drinking vessel is adapted to engage with and seal the opening of a bottle. The drinking vessel incorporates a frangibly linked portion which is adapted to, (a) engage with the bottle when the drinking vessel is fitted to the bottle to seal the bottle, and (b) remain with the bottle when the drinking vessel is subsequently removed from the bottle. Preferably the frangibly linked portion which is adapted to engage with the bottle is in the form of a ring.