A saw tooth shaped flexible rib in between a connector interface provides asymmetric sliding resistance and a one sided sealing effect. The asymmetric sliding resistance provides for low frictional engaging resistance and for a high disengaging resistance of the connector interface. The one sided sealing effect provides in conjunction with an interface cavity for back flow resistance into the cavity during disengagement movement in the interface and for a vacuum effect that assists in opposing the disengagement movement. The flexible rib may be monolithically fabricated together with the entire housing of the respective connector.