Sorry I don't recognize the fic, however I have a long complete two fic series (one is Charlie's POV one is Don's) where Charlie and Don have a falling out then Charlie moves out of the house, gets an apartment and pretty much severs ties with his family for a while. It's an angsty H/C cest fic, FWIW.

Conflict and Resolutions Series (http://emmademarais.livejournal.com/2006/02/15/)