Women smokers, Is it weird for me to get turned on when my gf smokes a cigarette?

It is weird cuz I have always been repulsed by girls who smoked cigarettes till I started dating this girl...I have never ever smoked....I find when she fires up a cigarette I get really hard....I think she may have noticed although I have tried to hide this fact from her...I am afraid she will find out...she I try to keep this info to myself...would you be upset if you found out your bf was turned on when you smoked a cigarette