Map Reference Table with NHibernate

I'm trying to map out some classes to use with NHibernate.  I have most things correct, however, I'm trying to map a reference table for Directors for movies.  

We have a few tables in the database, one being a Movies table that holds details about a particular movie.  Another table a Directors table that holds details pertaining to movie directors.  The problem is many directors can direct one movie, and one director can direct multiple movies.  So we created a reference table to show this:

MovieId | DirectorId
----------------------
      1             2
      2             2
      3             2
      1             4
      5             7

This way we can pull up all movies directed by a director and also list all directors for a particular movie.

How can I map this in NHibernate so that when I reference my Movie object I have a collection of directors for that movie, if any, and when I access my Director object, I have a collection of movies directed by him/her, if any?

Such as:

Movie movie = new Movie();
movie.Directors (type of IList<Directors>)  or something to that extent.

Director director = new Director();
director.Movies  (same as above IList<Movie>)

Thanks.