Some things are rude to do at the bar, some things aren't. Some things you do at the bar make you look cool; some make you look like a dork. Or cheap. Or dumb. Business Insider polled 30 bartenders on what they'd tell customers if they could, and here are some of their answers http://www.msn.com/en-us/foodanddrink/beverages/bartenders-share-13-things-theyd-love-to-tell-customers-but-cant/ss-BBESwlE?li=BBnb7Kz&ocid=HPCDHP#image=1