I don't drink (I never did), but I do go out a lot on the weekends. I'm never "off" from my calorie count, but I do sometimes choose foods that aren't the best. As long as I stay within my calories though, I'm fine.
It's actually pretty easy to eat nutritiously when going out. When I was losing weigh I just worried about the calories in foods, but I find that now I want healthier things such as more veggies
a lot of restaurants have these options and I can look up the nutritional information online. I've been able to stick to eating a lot of protein that way even when going out with my friends.