Bar & Nightlife Etiquette
If you are in a pub or bar, it's customary to leave a small tip on the bar for each drink ordered (usually around $1 each). If you plan to have several drinks you can leave your credit card with the bartender for future rounds (commonly called "opening a tab"), and then pay for all your drinks when you are ready to leave. Just make sure you let the bartender know which people or drinks you intend to pay for on your card, or you might end up buying drinks for more people in your party than you intended.
Also, if someone that you just met offers to buy you a drink (especially for women), it can be interpreted as a "pick up" -- in other words, an indication that they find you attractive. You may always turn down a drink that is offered to you by saying "no, thank you" or indicate that you're already attached to someone, and it is advised to do so if you are not interested in unwanted attention from the person who is offering it. If you accept the drink, you are not obligated to the person who offered it in any way, but they might reasonably expect some pleasant conversation from you while you are drinking it. It is also considered courteous to offer to pay for the next drink if someone else pays for yours, and this is a nice way of leaving the encounter neutral, neither indicating that you are attracted or not attracted to the person offering it, but that you are on friendly terms. If a person in a bar is rude to you in any way in this type of situation, you may simply excuse yourself and are not obligated to continue conversing with them.
It is no longer taboo to leave the bar ot club with someone you just met, although that doesn´t necissarily make it a GOOD idea! In the 1 or 2 hours in which you have have ¨gotten to know¨ your new friend, you honestly don´t know if they are a good person, or even a stalker, lunatic, rapist, or psycho killer. Take their number instead. Get to know them for a longer period of time in more sober circumstances. You never know. . .