As a former smoker, I say congratulations (!) for every part of your quitting journey that you accomplish. As for your husband's behavior, yes it's dumb, but I assume he's clueless about what it's like to give up smoking. You might start by telling him that quitting smoking is "monumentally aggravating" and please defer all conversations for at least a week. Other than that, "you've already had your last cigarrette," so stay strong.