I guess everyone I've ever smoked with has been really, really nice about it and I'm that fucker. Generally I smoke by myself, so maybe I'm not the most courteous smoker. I never think about things like that, and nobody has ever complained and people have asked me to smoke with them again...weird.
Well, I guess next time I know! Maybe more people will ask me to smoke with them.

(that goes for smoking from a bowl. with joints and blunts, i always spend as little time with it as possible because i don't like to waste others' weed).