a non - spillable drinking container is manufactured in assemblable parts which provide stackability and reduced manufacturing costs . the drinking container utilizes a perforated expandable diaphragm mounted or formed over a base plate . the container is preferably frustro - conical in shape to provide stackability . a drinking tube is attachable to the expandable diaphragm and a top is sealably mountable over the tube . drinking is accomplished by pulling upwardly on the tube to expand the diaphragm opening the perforations therein , allowing fluid flow through the perforations and up the straw to the mouth of the drinker .