diff --git a/app/models/concerns/metadata/unused_values_concern.rb b/app/models/concerns/metadata/unused_values_concern.rb
index 6f0a0bf1..79cdbe65 100644
--- a/app/models/concerns/metadata/unused_values_concern.rb
+++ b/app/models/concerns/metadata/unused_values_concern.rb
@@ -9,18 +9,22 @@ module Metadata
     extend ActiveSupport::Concern
 
     included do
-      # Genera un Hash de { title | slug => uuid }, excluyendo el Post
-      # actual y todos los que ya tengan una relación inversa, para no
-      # romperla.
+      # Excluye el Post actual y todos los que ya tengan una relación
+      # inversa, para no romperla.
       #
-      # @return [Hash]
+      # @return [Array]
       def values
         @values ||= posts.map do |p|
           next if p.uuid.value == post.uuid.value
-          next unless inverse? && (p[inverse].empty? || [p[inverse].value].flatten.include?(post.uuid.value))
 
-          [title(p), p.uuid.value]
-        end.compact.to_h
+          disabled = false
+
+          if inverse?
+            disabled = p[inverse].empty? || ![p[inverse].value].flatten.include?(post.uuid.value)
+          end
+
+          [title(p), p.uuid.value, disabled]
+        end.compact
       end
     end
   end
diff --git a/app/models/metadata_new_has_one.rb b/app/models/metadata_new_has_one.rb
index 642273e3..b75b14ae 100644
--- a/app/models/metadata_new_has_one.rb
+++ b/app/models/metadata_new_has_one.rb
@@ -1,6 +1,4 @@
 # frozen_string_literal: true
 
 # Nueva interfaz para relaciones 1:1
-class MetadataNewHasOne < MetadataHasOne
-  include Metadata::UnusedValuesConcern
-end
+class MetadataNewHasOne < MetadataHasOne; end
diff --git a/app/views/bootstrap/_custom_checkbox.haml b/app/views/bootstrap/_custom_checkbox.haml
index 73910a6f..dbef7516 100644
--- a/app/views/bootstrap/_custom_checkbox.haml
+++ b/app/views/bootstrap/_custom_checkbox.haml
@@ -1,6 +1,6 @@
 :ruby
   help_id = "#{id}_help"
-  checkbox_attributes = local_assigns.slice(:id, :type, :name, :value, :required, :checked, :data)
+  checkbox_attributes = local_assigns.slice(:id, :type, :name, :value, :required, :checked, :data, :disabled)
   checkbox_attributes[:type] ||= 'checkbox'
 
 .custom-control{ class: "custom-#{checkbox_attributes[:type]}" }
diff --git a/app/views/posts/attributes/_new_belongs_to.haml b/app/views/posts/attributes/_new_belongs_to.haml
index 849b3eff..661f3d27 100644
--- a/app/views/posts/attributes/_new_belongs_to.haml
+++ b/app/views/posts/attributes/_new_belongs_to.haml
@@ -56,9 +56,10 @@
 
     - content_for :"#{id}_body" do
       .form-group.mb-0{ id: value_list_id }
-        - metadata.values.each_pair do |value, uuid|
+        - metadata.values.each do |(value, uuid, disabled)|
           = render 'targets/array/item', value: uuid, 'send-value': uuid, 'human-value': value, class: 'mb-2' do
-            = render 'bootstrap/custom_checkbox', name: name, id: random_id, value: uuid, checked: metadata.value.include?(uuid), content: value, type: 'radio'
+            = render 'bootstrap/custom_checkbox', name: name, id: random_id, value: uuid, checked: metadata.value.include?(uuid), content: value, type: 'radio', disabled: disabled do
+              = t('posts.attributes.new_belongs_to.disabled') if disabled
 
     -#
       Según la definición del campo, si hay un filtro, tenemos que poder
diff --git a/app/views/posts/attributes/_new_has_many.haml b/app/views/posts/attributes/_new_has_many.haml
index e2d9d758..c46bc84a 100644
--- a/app/views/posts/attributes/_new_has_many.haml
+++ b/app/views/posts/attributes/_new_has_many.haml
@@ -57,9 +57,10 @@
 
     - content_for :"#{id}_body" do
       .form-group.mb-0{ id: value_list_id }
-        - metadata.values.each_pair do |value, uuid|
+        - metadata.values.each do |(value, uuid, disabled)|
           = render 'targets/array/item', value: uuid, 'send-value': uuid, 'human-value': value, class: 'mb-2' do
-            = render 'bootstrap/custom_checkbox', name: name, id: random_id, value: uuid, checked: metadata.value.include?(uuid), content: value, data: { action: 'required-checkbox#change', 'required-checkbox-target': 'checkbox' }
+            = render 'bootstrap/custom_checkbox', name: name, id: random_id, value: uuid, checked: metadata.value.include?(uuid), content: value, data: { action: 'required-checkbox#change', 'required-checkbox-target': 'checkbox' }, disabled: disabled do
+              = t('posts.attributes.new_has_many.disabled') if disabled
 
     -#
       Según la definición del campo, si hay un filtro, tenemos que poder
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 7ec6cf31..b717c666 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -765,6 +765,7 @@ en:
         label: Draft
       new_has_many:
         edit: "Edit"
+        disabled: "It's already associated to an article."
       new_has_and_belongs_to_many:
         edit: "Edit"
       new_predefined_array:
@@ -777,6 +778,7 @@ en:
         edit: "Edit"
       new_belongs_to:
         edit: "Edit"
+        disabled: "It's already associated to an article."
     required_checkbox:
       required: "Please select at least one option."
     reorder:
diff --git a/config/locales/es.yml b/config/locales/es.yml
index 12aef7ed..e41c8a41 100644
--- a/config/locales/es.yml
+++ b/config/locales/es.yml
@@ -773,6 +773,7 @@ es:
         label: Borrador
       new_has_many:
         edit: "Editar"
+        disabled: "Ya está relacionado con otro artículo."
       new_has_and_belongs_to_many:
         edit: "Editar"
       new_predefined_array:
@@ -787,6 +788,7 @@ es:
         edit: "Editar"
       new_belongs_to:
         edit: "Editar"
+        disabled: "Ya está relacionado con otro artículo."
     required_checkbox:
       required: "Seleccioná al menos una opción."
     reorder: