How can I ask someone subtly if they drink?

I like this guy, but the last time I liked someone I found out after 6 months that they got drunk every weekend and we're only 15. So now that I've met a new guy, I don't want to have to go through what I went through last time and waste 6 months of my life, but I've only talked to him like 3 times. How can I subtly ask him if he does drugs/drinks?