This just popped into my head after thinking about last night's Nip/Tuck episode. It really really bothered me that Christian is still cheating on Kimber, even after she underwent a medical procedure for him, that caused permanent, tragic damage. So here it is:
The more you try to hold an irresponsible/imature person accountable, the more likely you are to end up being dragged along as a sap or a fool. Adding insult to injury.
Better step away while you're still ahead of the game. Let them spiral (or crash) down on to rock bottom (or terra firme) on their own. After all, all good, irresponsible rides come to an end, eventually.