Deleting records from embeds_many relation, doesn't destroy record.

[tcopple]

When I try to delete an attachment through an 'embeds_many' relation, using the _delete key generated by a form, the attachment is deleted but the record remains with it's paperclip
fields set to nil. How do I delete the record from the relation?

class User
  include Mongoid::Document

  embeds_many :photos, cascade_callbacks => true
  accepts_nested_attributes_for :photos, :allow_destroy => true
end

class Photo
  include Monogoid::Document

  has_mongoid_attached_file :attachment
  embedded_in :shopping_center, :inverse_of => :photos
end

When I submit my form to remove the first attachment here's the request that's generated:

{..., "user"=>{
        "photos_attributes"=>{
           "0"=>{"_destroy"=>"1", "id"=>"4f5e30440cc47d6c5400002d"}, 
           "1"=>{"_destroy"=>"false", "id"=>"4f5e30440cc47d6c5400002e"}
         }
       }, 
...}

However when the request is processed through the controller:

class UsersController < ApplicationController
  def update
    @user.= User.find(params[:id])
    @user.update_attributes(params[:user]

    #rendering code here
   end
end

Paperclip issues the appropriate Deleting attachments messages, but then when I view the model, the record still exists. The underlying file has been removed, and all the paperclip fields on the Photo class have been set to nil.

How do I ensure the record is removed from the relation?