A container assembly to facilitate liquid transfer from a donor container to a recipient container that includes utilizing a first container and a second container, whereby the second container has a piston coupled to a sidewall thereon in a watertight configuration and that is operably configured to linearly translate within a second container cavity. The assembly includes a container linking structure selectively removably couplable to the second container in a watertight and male-female coupling configuration, a stem member selectively removably couplable to the piston in a male-female coupling configuration and having a grasping portion thereon, and a straw member attached to the linking structure, wherein the stem member is configured to apply a force on the piston to linearly translate the piston to generate a negative pressure within the enclosed conduit for transportation of liquid configured to be housed in the first container cavity to the second container.