Abstract: A two container assembly comprises a first container for containing a fluid and a second container for containing a fluid. The first container has a handle and a handle opening, and the second container has a resilient sidewall, a top end and a bottom end. The second container is dimensioned to fit into the handle opening of the first container. The two container assembly has a means for snap-fitting the second container into the handle opening or frictionally engaging the second container in the handle opening. The means for snap-fitting preferably comprises a concave portion in the resilient sidewall of the second container. The concave portion has a shape that mates with a convex shaped portion of the handle. For example, the handle may have an oval cross-section. Also, the second container has a top-to-bottom axis which is substantially perpendicular to a top-to-bottom axis of the first container when the second container is located in the handle opening.