title: Delete the relations of relations in Laravel 5.2
body: <p>I'm trying to delete the relations of the relations of a model. If that makes any sense?</p>
  
  <p><code>$post-&gt;comments()-&gt;activities()-&gt;delete();</code></p>
  
  <p>So my post model has comments and comments have activities. Whenever I try to execute this, I get this error:</p>
  
  <p><code>Call to undefined method Illuminate\Database\Query\Builder::activities()</code></p>
  
  <p>I know that this works:</p>
  
  <pre><code>$post-&gt;load('comments.activities');
  
  foreach ($post-&gt;comments as $comment) {
      $comment-&gt;activities()-&gt;delete();
      $comment-&gt;delete();
  }
  </code></pre>
  
  <p>But I think the first solution looks cleaner. Does anyone know why this won't work? Thanks.</p>
  
  <p><strong>Edit</strong></p>
  
  <p>The relationship method in Post model (polymorphic because there are comments on the post and comments on comments).</p>
  
  <pre><code>public function comments()
  {
      return $this-&gt;morphMany('App\Models\Comment', 'commentable');
  }
  </code></pre>
  
  <p>The relationship methods in Comment model (polymorphic because I use activities on multiple models).</p>
  
  <pre><code>public function activities()
  {
     return $this-&gt;morphMany('App\Models\Activity', 'subject');
  }
  </code></pre>