I have the following models in Rails 4 with a simple has_many :through association: class Model < ActiveRecord::Base has_many :model_options has_many :options, through: :model_options end class Option < ActiveRecord::Base has_many :model_options has_many :models, through: :model_options end class ModelOption < ActiveRecord::Base belongs_to :model belongs_to :option end I want to be able to iterate