gistfile1.rb

class User
  has_and_belongs_to_many :followers, :class_name => "User", :inverse_of => :followings
  has_and_belongs_to_many :followings, :class_name => "User", :inverse_of => :followers
  has_and_belongs_to_many :club_followings, :class_name => "Club", :inverse_of => :followers
end

class Club
  has_and_belongs_to_many :followers, :class_name => "User", :inverse_of => :club_followings
end

# OR if polymorphic worked with habtm

class User
  has_and_belongs_to_many :followers, :polymorphic => true, :inverse_of => :followings
  has_and_belongs_to_many :followings, :polymorphic => true, :inverse_of => :followers
end

class Club
  has_and_belongs_to_many :followers, :polymorphic => true, :inverse_of => :followings
end