Assuming you are using a SQL DB, you could do:
#In your user model:
has_and_belongs_to_many :friends, :class_name => "User",
:foreign_key => "other_user_id"
#in your controller
@friends = UsersUser.where(:status=>friend && :user_id => current_user.id)
@friends_out = UsersUser.where(:status=>pending && :other_user_id => current_user.id)
@friends_in = UsersUser.where(:status=>pending && :user_id => current_user.id)
So in this example if you wanted to be a friend with me, your id would be the other_user_id and mine would be user_id and the status could be set to pending, if I accept you could change the status to accepted or however you would like.
Also if @user is equal to the current logged in user, in your view you could just call @user.friends to get all of your friends regardless of status.
the UsersUser model you have there is similar to the Friendship model in
You way adds a status, so you just need to accept those who have added you.
I understand what you are doing now with status, is saves the cross referencial query.