Saving EntityRef and EntitySet objects Automatically

Question

Say I have an entity that looks as follows

public Order OrderEntity 
{
   EntityRef<Customer> CustomerEntity;
   EntitySet<OrderDetail> OrderDetailEntity;
   ...
   ...
}

When I save a OrderEntity, L2S, will want to also save the entity in CustomerEntity and all the entities in OrderDetailEntity. Sometimes we want this behavior and sometimes we do not. For those times we do not, how to tell L2S not to do this?

Thanks - Randy