Abstract: A quick-connect tubing coupling comprising a cup-shaped cage externally attached to a first tube with an end portion of the tube concentrically contained within the cage. The inside diameter of the cage is sufficiently greater than the outside diameter of the tube portion contained therein to provide a space therebetween. The cage has a plurality of axially extending cantilevered leaf springs projecting radially inwardly toward the first tube portion, some of the leaf springs being longer than the others.A second tube is outwardly cupped at one end to encapsulate an O-ring, the cupped end portion of the second tube being concentrically received between the cage and the first tube end portion. The cupped end of the second tube provides a shoulder behind which the longer leaf springs can lock with the O-ring in a sealed mode or behind which the shorter leaf springs can lock with the first and second tubes axially displaced to provide a pressure relief vent.