fmc_apprentice, I SO understand and empathize with you. I myself have just started my career as FO and some of the captains smoke too!
Usually, when they ask me if I mind (obviously expecting a "no"-answer), I reply, "One, here and there won't bother me", kind of implying that I DO mind the smoking but at the same time I am tolerant of one or too. When I get home my hair and clothes are stinking of smoke and after a long flight I usually get a headache. Leaving the flight deck is a very good idea, and one which I haven't tried yet, however, what to do with a chain smoker? Stay in the loo all the flight?
Another consideration which hasn't been given...I believe some companies allow female first officers to fly till they are a few months pregnant. Will any consideration be given by these captains, in these cases? Or do they end up "twitching wrecks"?
DSR10, I think you do not know how invasive cigarette smoke is to a non-smoking person. Us non-smokers are not "picking" on smokers but just asking for a compromise.