Can I sue the hookah bars that let's my underage (15 and 16 year old) friends in and let's them smoke?

Call the police and tell them about the problem. You probably don?t have standing to file a law suit and if the owners of the bars are allowing minors to do something illegal, the police are the best ones to deal with the issue.

No, you can't sue, because even if there was a cause of action, which is dubious, you would not have standing. What this means is there must be a legally accepted basis on which to sue, which is called a cause of action. And there person suing must be a party who has been damaged in some way, which gives them standing, which is the right to sue. If you are really concerned, call the city where the hookah bars are located and say you want to file a complaint with the city. I think smoking is not healthy, but the amount of smoking that happens at a hookah bar is minimal. It is more about having the exotic experience. It seems like your friends are having fun going out and experiencing a different culture. It seems like a basically harmless experience that they think is cool enough to post pics on their facebook. If they have fun in such a harmless way, I'd say leave them alone. If you want to get involved in an important cause involving your classmates, how about encouraging them to always wear their seatbelts and to never put too many people into one vehicle.