multidimensional array of inputs - Jquery Validation plugin

I'm having some trouble trying to figure out how to change the required message for some fields in my form. I have created a form where users can add or remove fields at their will.

So I have something like this:

div class="group">
            <h3>Sexe</h3>
            <label class="radio-label"><input type="radio" name="enfants[<?php echo $i; ?>][sexe]" value="Garçon" class="required" /><span class="text">Garçon</span></label>
            <label class="radio-label"><input type="radio" name="enfants[<?php echo $i; ?>][sexe]" value="Fille" class="required" /><span class="text">Fille</span></label>
        </div>

As you can see, I have a dynamic number created via php (if js is disabled). If enabled, the user adds fields and it generates a random number for it. Everything works at this point.

This is the code for validation:

form.validate({

        rules: {
            parent_telephone_maison: {
                require_from_group: [1, ".phone-group"]
            },
            parent_telephone_cell: {
                require_from_group: [1, ".phone-group"]
            },
            parent_telephone_travail: {
                require_from_group: [1, ".phone-group"]
            },
            autre_telephone_maison: {
                require_from_group: [1, ".autre-group"]
            },
            autre_telephone_cell: {
                require_from_group: [1, ".autre-group"]
            },
            autre_telephone_travail: {
                require_from_group: [1, ".autre-group"]
            }
        },
        errorPlacement:
          function(error, element) {

            var id = element[0]['id'];
            if (element.attr('type') === 'radio') {

                var group = $(element).closest('.group');
                var textarea = group.find('textarea').closest('[data-rel]');
                if (textarea.length >= 1) {
                    textarea.before("<label for='"+id+"' class='error'>You need to choose an option.</label>");
                } else {
                    group.append( "<label for='"+id+"' class='error'>You need to choose an option.</label>" );
                }


            }
        }
    });

As you can notice, I have tried to use the errorPlacement method to achieve what I needed. It worked, but each time I click on a radio button, the error is duplicating.

Is there a way to code this with the messages method? To be honest, I am not quite sure how to write it down.

I hope this is clear, I can provide more information if needed. And as always, thanks for your help.