Disappeared parent in Mongoid after_destroy

disappeared_parent.rb

class Parent
  include Mongoid::Document
  embeds_many :children
  before_create :create_children
  before_destroy :destroy_children
  
  private
  def create_children
    3.times { children.build }
  end
  
  def destroy_children
    children.destroy_all
  end
end

class Child
  include Mongoid::Document
  embedded_in :parent
  before_destroy :do_something_related_to_parent
  
  private
  def do_something_related_to_parent
    parent.children # ERROR: undefined method `children' for nil:NilClass
  end
end

Parent.create.destroy

Having the same issue with Mongoid 2.1.5. Have you found the issue with this? In my case before_destroy was ok. But parent returned nil when its called from after_destroy callback.