You should leave if you don't like it. As long as it is in a place where smoking is allowed, it's your responsibility to look out for your own health and leave. Just because you don't like the smell, you don't have to be a dick and tell them to move. If you sat down next to someone who hadn't showered in a week, would you move, or tell them they had to move? Same concept.
You clearly didn't read my post properly. I specifically said I don't care about the health side of it.
And yes, if I am sitting somewhere and a person who stinks comes up and sits next to me, I will tell them to move and I will politely tell them that they stink. Whether it be of stale cigarettes or of body odour.
Your example was not the same concept either; I would never chose to sit next to a someone and then ask them to move, that's ridiculous.

