just drink.
if you mix things, mix them with diet pop so you're not having extra bad calories. drink a protein shake mixed in water and take a multivitamin before hand and you'll be fine.
yeah, you can sit in your room by yourself on the weekend or go out and be the weird guy that just stands there sober while everybody else has fun.
but listen, you're posting this at sosuave, so you're probably working out with looks in mind, not to be a pro bodybuilder or for sports or anything.
will it slow your gains? sure. will you put on fat at a slight faster rate than usual? of course. But, you sure aren't gonna notice the difference in your gains. it's not like you'll be like "oh man, I could lift this much heavier if I didn't drink last weekend" and as a drinker I can tell you, that the amount of fat I put on from the beer, whiskey, and other **** I drink is very little. barely even exists. granted that might be because I have a decent metabolism, but I know a lot of guys that drink on the weekends and still look pretty cut. Just don't drink everyday. have fun on the weekends. you might want to throw in a cardio session every once in a while if you feel like you're putting on too much beer fat. And never, EVER drink when you're cutting.
You'll be fine. Live while you can. Remember, there's no difference between a nerd who stays in every friday night to play Halo or a guy that stays home every friday to make sure he gets the most out of his gains. Both aren't out living and it's a god damn shame both ways. Especially if you're just lifting for looks.