that is the definition of addiction - knowing better, but can't seem to stop oneself, which in turn creates disappointment and regret within one's self. It's admitting to yourself that if you open the door even a crack, it'll walk right back in and take over your life again. As for yourself, well getting angry or upset is NOT going to help either of you and you'll just lose your own strength and centeredness. If you can't accept that he's a pot smoker and may be for awhile, then I would leave and move on. He'll either quit because he begins to realize the price he's paying for his pot habit OR he'll continue and you will move on without living in a fantasy for years that "he'll change someday , I know he will" . That's just my opinion. Good luck.