JavaFX .hide function not working

I want to make a simply program consisting of two windows. The first window has a check box. If you select it: the second window is shown. If you deselect it: the second window is hidden. I tested this out with print line statements and it worked. But when I implemented the code for the second stage: the hide function isn't working. Anyone know why?

public void show() throws IOException{
        Stage secondaryStage = new Stage();

        FXMLLoader loader = new 
            FXMLLoader(Main.class.getResource("second.fxml"));
        AnchorPane root = loader.load();
        Scene scene = new Scene (root);
        secondaryStage.setScene(scene);


        if(check.isSelected()){secondaryStage.show();
        }

        else {secondaryStage.hide();}

    }