A connector is disclosed that has a housing having a fluid path from a first port through an internal cavity to a second port. The connector also includes a plug that has first and second positions within the internal cavity where the plug blocks the fluid path between the first port and the internal cavity when in the first position. The plug has a diaphragm that separates the internal cavity into a first volume that is vented and a second volume that includes the fluid path. The plug also includes a biasing element that is disposed within the first volume and that urges the plug toward the first position. Displacement of the plug from the first position toward the second position opens the fluid path and increases the second volume.