A water drinking device for pets, includes a cup including a bottom, and a wall extending upwardly from the bottom and defining an inner hollow constructed so that a bottle with water can be received in the inner hollow and held in it and thereafter removed from the inner hollow of the wall for pouring water from the bottle into the inner hollow to allow a pet to drink water from it, and the wall is transversely stretchable and contractible such that when a bottle with a transverse dimension that is greater than a transverse dimension of the inner hollow is inserted into the latter, the wall stretches transversely outwardly, and upon removal of the bottle from the inner hollow the wall contracts back to its initial transverse size, and the wall is also constructed so that the cup is insertable into a cup holder of a vehicle.
