deleted object would be re-saved by cascade (remove deleted object from associations) hibernate

I am using C# with NHibernate ORM,
When I Am Trying To Delete An Object Data, It is Showing Exception

"ObjectDeletedException was caught
deleted object would be re-saved by cascade (remove deleted object from associations)
[Application.Domain.ContactAddress#327] "

How can I Rectify It...Help Me...

The Code Is Below That I Had Used To Delete
public void Delete(TEntity t)
{
using (var tx = Session.BeginTransaction())
{
try
{
Session.Delete(t);

tx.Commit();
}
catch (Exception ex)
{
tx.Rollback();
}
}
}