code: function() {
  			Backbone.Relational.store.getCollection( this.instance )
  				.unbind( 'relational:remove', this._modelRemovedFromCollection );
  			
  			Backbone.Relational.store.getCollection( this.relatedModel )
  				.unbind( 'relational:add', this._relatedModelAdded )
  				.unbind( 'relational:remove', this._relatedModelRemoved );
  			
  			_.each( this.getReverseRelations(), function( relation ) {
  					relation.removeRelated( this.instance );
  				}, this );
  		}
docs: Cleanup. Get reverse relation, call removeRelated on each.