I am trying to define a colleagues association table that can be used to notify people when there colleagues make changes. Think of it as a Facebook "followers" type of thing. The relationship is not necessary inverse. I may follow James Watson, he might not (yet) follow me. ;-) Anyhow, here is where I am at, but SQL Alchemy wants a fully bidirectional relationship and complains Colleague_Association.table = Table( "colleague_association", metadata, Column( "id", Integer, primary_key=True ), Column( "user_id", Integer, ForeignKey( "galaxy_user.id" ), index=True ), Column( "colleague_user_id", Integer, ForeignKey( "galaxy_user.id" ), index=True ) , Column( "deleted", Boolean, default=False ) ) assign_mapper( context, Colleague_Association, Colleague_Association.table, properties=dict( user=relation( User, backref="colleagues" ), colleague=relation( User ) )) There are examples on the web for doing this in more recent versions of SQLAlchemy, but I can't find one that uses the (now deprecated) assign_mapper method. Any ideas? Thanks, Ted