title: Reverse look-up with related name
body: <p>Suppose these models:</p>
  <pre><code>class Person (models.Model):
      pass
  </code></pre>
  <p>and</p>
  <pre><code>class Marriage (models.Model):
      person = models.ForeignKey(Person, on_delete = models.CASCADE, related_name='person')
      person_2 = models.ForeignKey(Person, on_delete = models.CASCADE, related_name='person_2')
  </code></pre>
  <p>How can I filter persons through the ID of a Marriage field (e.g. the ID)? That is, my goal is to do something like Person.objects.filter(marriage__id=32). I understand that the related name has some role there, but for example Person.objects.filter(person_2__marriage__id=32) doesn't seem to work either.</p>
  <p>Thank you!</p>