Could it possibly be Purified By Innocence http://virtualpersonal.livejournal.com/205659.html

YES! Lol shouldve known it was Sam/Dean when I remembered the exorcism parts.

Thank you!

Title: Purified By Innocence
Authors: Cas ([info]virtualpersonal) and Fetish [info]lady_fetish
Pairing: Dean/Sam
Rating/Warnings: NC 17; attempted rape (not BY the boys)
Characters: The characters are not ours, we're just playin' with 'em
Concrits: welcome in comments.

Summary: Lord Dean Winchester belongs to the secret arm of the Knights Templer, fighting supernatural horrors and demons that plague the land. Knights like Dean must be paired with an innocent who can neutralize the dark taint that builds up inside them due to their close contact with evil. Dean has selected the boy, Sam, as his innocent, and goes to claim him from the monks who have groomed and sheltered him for that purpose.

http://virtualpersonal.livejournal.com/205659.html


There is a sequel as well: Keeping the Home Fires Burning

Thank you so much, this is it.

The sequel was written by another author, with permission of the original authors. Sequel can be found at
http://phx69.livejournal.com/tag/home%20fires%20fic