A device for transferring liquids from between containers, and methods for its use. The device includes a body having an axis and first and second cap members at oppositely-disposed axial ends of the body. Cavities are present within the first and second cap members and define axial openings in the body. The cavities are coaxially aligned along the axis of the body and define interior walls within the first and second cap members on which female threads are formed. At least one fluid passage is within the body and fluidically interconnects the cavities. The axial openings in the body are configured to receive necks of first and second containers, and the female threads are configured to couple with male threads on the necks of the first and second containers such that the device physically couples the first and second containers together.