public IList<Contact> GetContacts(Submission submission)
{
   IList<Contact> results = (
      from contact in submission.Contacts
      where submission.PrimaryContact != contact
      select contact
   ).ToList();

   return results;
}

  <class name="Suite.Framework.Core.Impl.Contact, Suite.Framework.Data" table="dt_Contact">
    <id name="Id" access="nosetter.camelcase-underscore" column="ContactId">
      <generator class="guid" />
    </id>
    <property name="Email" />
    <property name="LastName" />
    <property name="FirstName" />
    <many-to-one name="Address" class="Suite.Framework.Core.Impl.Address, Suite.Framework.Data" column="AddressId" cascade="all" />
    <bag name="Submissions" table="rt_Contact" lazy="true" inverse="true">
      <key column="ContactId" />
      <many-to-many class="Suite.Framework.Core.Impl.Submission, Suite.Framework.Data" column="SubmissionId" />
    </bag>
  </class>

  <class name="Suite.Framework.Core.Impl.Submission, Suite.Framework.Data" table="dt_Submission">
    <id name="Id" access="nosetter.camelcase-underscore" column="SubmissionId">
      <generator class="guid" />
    </id>
    <property name="Created" />
    <many-to-one name="PrimaryContact" class="Suite.Framework.Core.Impl.Contact, Suite.Framework.Data" column="PrimaryContactId" cascade="none" />
    <many-to-one name="CreatedBy" class="Suite.Framework.Core.Impl.Contact, Suite.Framework.Data" column="CreatedBy" cascade="none" />
    <bag name="Contacts" table="rt_Contact" lazy="true">
      <key column="SubmissionId" />
      <many-to-many class="Suite.Framework.Core.Impl.Contact, Suite.Framework.Data" column="ContactId" />
    </bag>
  </class>