<human>: Could you distill the essence of the text into 1-3 sentences?

Alright so we've been dating for 3 and a half years, and we've had a pretty good relationship. There've been a lot of bumps along the way, but we're more or less very happy now. So, I guess some backstory about him. He's a partier. Always has been. This summer, I got a full time job at my university, and he just worked his part-time job. He started going to this bar [I've been there a couple of times and it's a shit bar, total dump] every single weekend, and every weekend he'd get drunk and party super late. He also loves getting high [weed mostly] which I don't mind, but around mid-summer he admitted that he tried cocaine with his best friend at this bar. I got pretty upset with him over it because he said he'd never do hard stuff. He assured me that it made him feel disgusting and he never wanted to do it again [he was very sluggish/tired/etc. so I believed him]

Fast forward to now; he left his Facebook message open to this guy he's become friends with at that bar talking about how he was at a private party and there was loads of coke and everything, and my BF replied saying it sounded like a sick party. Scrolling through other messages, I saw hints that maybe he's been doing more than just drinking.

I have zero idea how to ask him about this. I don't want to tell him I was going through his Facebook messages, but I'm scared he's going to get too far into this and ruin his life or something. I have no idea how to bring it up, and if I do, how do I know he isn't lying if he says he isn't doing it? [I got pissed the first time he told me, so naturally I assume he wouldn;t want to tell me again]

How do I bring this up? Should I bring it up? What the **** do I do?
<bot>: I think my BF might be doing hard drugs every now and then but I don't know how to confront him without admitting I snooped. How do I bring this up with him?