Smoking, that’s a weird one for me. I don’t like when smoke blows in my face, true enough, but I’m usually just content to let smokers be (and/or leave the area if possible). The only time it ever really irritated me was when I was riding in the backseat of my friend’s car, and our acquaintance was in the front. Said acquaintance lit up a cigarette, took a drag, and THEN asked me “Oh, is it okay if I smoke?†I’m just like, well what am I gonna do about it now, dude? You already lit up.
That’s only happened once, but if it ever happens again I can for sure call it a pet peeve. It's rude, in any case.