I think i found the solution…See here for more details: http://social.msdn.microsoft.com/Forums/en-US/adodotnetentityframework/thread/47296641-0426-49c2-b048-bf890c6d6af2/
Essentially you want to make the ICollection type protected and use this as the backing collection for the public IEnumerable
public class Product
{
// This is a mapped property
protected virtual ICollection<Photo> _photos { get; set; }
// This is an un-mapped property that just wraps _photos
public IEnumerable<Photo> Photos
{
get { return _photos; }
}
public void AddPhoto(){...}
public void RemovePhoto(){...}
}
For lazy loading to work the type must implement ICollection and the access must be public or protected.