If i share a cigarette with someone who has a wart on his lip, do i catch a wart too? if so is there a lot of probability?

Big picture: Paul, please do everything that you possibly can to stop smoking. Lung cancer is a horrible disease and you're asking for it by smoking; you're also guaranteeing that your level of physical fitness and ability to exercise will be less now and far less in later life than it would be if you're a non-smoker. You're worrying instead about a wart on your lip? Take that health concern and translate it.