Cannot validates_associated of foreign_key object

Using rails 3 and ruby 1.9.2 p0 on win 7 x64.
When I use validates_associated with the following code and try to create a "Users Friend", I get the following error returned

NoMethodError (undefined method valid?' for 3:Fixnum):<br/> app/controllers/users_friends_controller.rb:46:inblock in create' app/controllers/users_friends_controller.rb:45:in create'

Code:
users_friend model:

class UsersFriend < ActiveRecord::Base
  belongs_to :user, :class_name => "User", :foreign_key => :requester
  belongs_to :user, :class_name => "User", :foreign_key => :requestee
  validates_associated       :requester, :requestee
end

user model:

class User < ActiveRecord::Base
  has_many :users_friends, :dependent => :destroy
  has_many :friends, :through => :users_friends
end

migration:

class CreatePlayersFriends < ActiveRecord::Migration
  def self.up
   create_table :users_friends do |t|
    t.integer :requester
    t.integer :requestee

    t.timestamps
   end

   create_table :users do |t|
    t.string :name

    t.timestamps
   end
  end

 def self.down
   drop_table :players_friends
 end
end

In the console:

user = User.new(:name => test).save
friend = UsersFriend.new(:requestee => 1, :requester => 1).save