reducing hubs' alcohol intake??

Kristy
Not trying to be controlling- but I need help/advice as to what's maybe worked for others? 
Husband has a mild issue with social drinking, he tends to blackout and smoke a lot of cigarettes. It's been an ongoing issue since I got pregnant. (5 mo. now) but he has since tapered off almost completely. 
Now, one of his best friend's bachelor party is this weekend. I'd be Satan if I asked him not to go and/or not to drink if he went. So I'm wondering if we can come to a compromise as to how much he indulges. I.e. Only beer/no liquor, or like 6 drinks per night or something? 
I haven't brought it up yet since idk if it's even a fair idea or if he'd even comply. No hate please.