Recently I have started to become concerned about DS's behaviour. I am basically worried about what he is doing when out and about with mates. He thinks he is very cool (lol) and spends a lot of time out with friends. Recently he came home smelling of weed, he denied being high but I could tell he had been round it and very possibly had done it (I'm no expert). He sometimes goes to parties and has come home drunk a couple of times. I guess this is fairly normal for a 16 y/o (He's year 11), although some people may disagree.
Anyway there's the background. For NYE he says he is going out with friends/to a friends house, it's all pretty vague. I heard a group of them chatting about how it was gonna be mental. I basically want to tell him he has to join me and family with celebrations (we have people round, including a family whose kids he knows - although wouldn't choose to spend time with). AIBU to say no to going out with his friends (As am concerned it could end up messy/with drugs etc).
I know this is a bigger issue than just one night, and have spoken to him at length about drugs/alcohol previously, but I just feel with NYE I could minimise it. Opinions?