A connector for connecting two furniture modules or other stationary objects to form a modular system. The connector includes two hardware pieces, to be mounted onto two furniture modules, respectively. The first piece fits into the second piece in a loading/unloading position, and then moves to a locked position where prongs of the first piece are dovetailed with slots of the second piece. A detent on one hardware piece and a track in the other hardware piece are provided to help the first piece stay in the locked position, but to allow the first piece to move out of the locked position into the loading/unloading position when sufficient force is applied. A furniture unit formed by joining multiple modules using the connector can safely withstand reasonable outside forces in various directions without shifting or separating. The system also allows for easy and intuitive unlocking/dismounting to separate the two modules.