Just tell them that you're not interested in drinking, and either they roll with it or they don't. Chances are, they'll probably try to introduce different conversational subject matter that has nothing to do with drinking which can (admittedly) be hit or miss. This will also help you gauge how often your friends drink, and how much. I can say this myself because I used to have a pretty goddamned serious drinking problem...as in I was once legally drinking an excess maximum of the state allowance per bottle in my U.S. state over the course of a 2-day weekend, while working 60+ hours a week, and being on the lower side of an average BMI to an underweight BMI. I was trying to kill myself with alcohol during that time period...I cut myself off right before it got bad, like really, medically bad kind of a deal. I think the worst part about that is that it totally messed up my alcohol tolerance. These days I can be sober for up to 90 days, and still have a tolerance of at least six shots of whiskey before I get a buzz and that was...like 3 or 4 years ago?? I drink less as I get older.Except for specifically today, wherein I'm inclined to drink as if Caesar (and effectively all of the Roman autocracy) himself commands me to.