Mapping a one-way ManyToMany?

Question

I want to map the following company to the below address. I want it to be a one way relationship since the address class is being used by several other classes.

When I generate the schema the junction table is created successfully but when I try to save an entity nothing is persisted in the junction table. Only in address and company tables. What do I need to do to make this work?

public CompanyMapping()
{
    Map(x => x.Name);

    HasManyToMany(x => x.Addresses);
}

public AddressMapping()
{
    Id(x => x.Id);

    Map(x => x.AddressLineOne)
        .Not.Nullable();

    Map(x => x.AddressLineTwo)
        .Nullable();

    Map(x => x.PostCode)
        .Not.Nullable();

    Map(x => x.City)
        .Not.Nullable();
}

public class HasManyToManyCascadeConvention : IHasManyToManyConvention
{
    public void Apply(IManyToManyCollectionInstance instance)
    {
        instance.Cascade.All();
        instance.Inverse();
        instance.Key.ForeignKey(Inflector.Underscore("fk_" + instance.EntityType.Name + "_" + instance.ChildType.Name));
    }
}

<class xmlns="urn:nhibernate-mapping-2.2" name="Company" table="`company´">
    <id name="Id">
        <column name="company_id" />
        <generator class="identity" />
    </id>
    <bag table="company_address" lazy="false" cascade="save-update" name="Addresses">
        <key column="company_id" />
        <many-to-many class="Address" column="address_id" />
    </bag>
    <property name="Name">
        <column name="name" />
    </property>
</class>

EDIT 2010-11-05: If I add mappings for BillingAddress and DeliveryAddress like this I don't have any problems.

References(x => x.BillingAddress)
    .Column("billing_address_id")
    .ForeignKey("fk_account_billing_address")
    .Cascade.All()
    .Fetch.Join();

References(x => x.DeliveryAddress)
    .Column("delivery_address_id")
    .ForeignKey("fk_account_delivery_address")
    .Cascade.All()
    .Fetch.Join();

Answer 1

You need to tell nHibernate which side of the collection wears the pants. See if this works:

HasManyToMany(x => x.Addresses)
    .Inverse()
    .Cascade.All();