Fic search

 Hey guys, I'm looking for a fic that I lost.  In it Morgan and Reid are in a bdsm relationship.  During one of the cases, the unsub kills submissive partners who are wearing collars.  Morgan and Reid have a fight, and Reid doesn't take off his collar when he leaves, which leads to the unsub trying to kill him.  Derek and the team got there in time and I remember at the end when Reid was in the hospital they explained to everyone about their relationship.

Thanks in advance!