code: def exists(self, user, status=None, symmetrical=False):
          
          query = dict(
              to_users__from_user=self.instance,
              to_users__to_user=user,
              to_users__site__pk=settings.SITE_ID,
          )
  
          if status:
              query.update(to_users__status=status)
  
          if symmetrical:
              query.update(
                  from_users__to_user=self.instance,
                  from_users__from_user=user,
                  from_users__site__pk=settings.SITE_ID
              )
  
              if status:
                  query.update(from_users__status=status)
  
          return User.objects.filter(**query).exists()
docs: Returns boolean whether or not a relationship exists between the given
          users.  An optional :class:`RelationshipStatus` instance can be specified.