Pichacho, I was in the exact same situation as your girlfriend with my ex, and the worst thing is at the start of the relationship he said, right, I love you but if I catch you taking any Class A's it's over.

I was fine with that at the start but then it turned to no weed.....then no alchohol during the week....it got to the point where if I lit up a fag in a bar or something, he would ignore me for the next half hour.

I'm sure you're not as extreme as he was, but for all his other great qualities and even tho his intentions were honest, those attempts to control me resulted in my leaving and breaking his heart...

If you're g/f was a smoker when you started going out then it's really not fair to expect her to change a part of her personality for you. You should love her regardless. Maybe if you compromise and ask her if she would consider giving up when/if she gets pregnant. She has the right to harm her body, but not your baby's.

All I'm saying is, just don't let it get to a 'me or the cigarettes' situation because you might not be happy with her choice....