I have situation where I am starting an asynchronous operation and passing two persistent entities to the asynchronous operation. The persistent entities may have some assosciations that havent been loaded yet. So I need to start a new session within the asynchronous operation so that I can lazy load the assosciations.

I have tried to attach the persistent objects to the new session with Lock, but I get an NHibernate.LazyInitializationException. The error message is "Illegally attempted to associate a proxy with two open Sessions".

So I am wondering if it is possible to associate an object with another session without evicting it from the first session.

Or if there is a better solution to solve my problem. thanks for any help.

Which of the multiple sessions (and transactions) should the object then use to load itself?

The object could be potentially be loaded by both.

So it sounds like I need two instances of the object, one for each session. Is there any way to do this without re-loading the object from the database?

If it could be loaded by both sessions, it could break transaction isolation.

NH does not have any API for copying objects, you have to do it yourself. Or if you have the second-level cache enabled, you can just try loading the object by id, it should be reloaded from the cache.