Smoking (🍃) in vatican city

Friends of mine went on a holiday in Italy last summer. Since they are all smokers, they brought something to smoke (not tobacco) and even smoked a joint in vatican city. I know the risks and that it is extremely but I'm going to Rome this year with some other friends and we're going to smoke there too. Do you guys have any tips, we know it's dumb and risky but I want to smoke a joint there.