Situations I'm most interested in:
-They're married/in a very serious relationship when one of them becomes an addict and the other one doesn't know whether to stay and save them or leave for their own safety and sanity
-They break up which leads to one of them turning to drugs/alcohol
-They break up because of the addiction
-They have kids together and are divorcing so part of the custody nightmare is that whoever has the addiction might lose the kids
-They have kids together and the addiction affects the kid(s)
-Kurt and Blaine have been broken up for a while and they meet again and one of them is an addict
Thanks for all the help.