17 year old getting invited to go drinking

[PerkyGoldCat]

My son has just turned 17 years old and is still in school. His Dad left when he was a baby, so he has grown up without a father. My brother in-law (who has two kids of his own, 14 and 12 years old) has always stepped up as sort of a father figure, teaching my son handy things like how to fix broken items around the house, building projects, fixing cars etc. They had also done activities together such as off road cycling and nights of gaming together. Which I had always appreciated and thought it was good for my son.
However, the past 3 or 4 months, my brother in-law has been inviting my son over for drinks, which I am not comfortable with. I do allow my son to have a drink occasionally in a controlled and safe environment. It just seems that lately when he does go out with my brother in-law, he always comes home past curfew and does not follow the rules of letting me know where he is. The past weekend, my son was over at a friends house, and my brother in-law insisted on going out for a drink and picked up my son along with his 4 friends (who are between 15 and 17 years old), he then took all of them out for drink.
When I express that I am not happy about this to my brother in-law, he says that my son is an adult and can make his own decisions. This way of thinking also seems to be rubbing of on my son, and there seems to be no respect from both of them for my rules when they are together lately.

Firstly, am I the only one that thinks its weird for an adult to hang out with teenagers? And secondly, please give me advise, I don't want to ruin their friendship and be the reason thereof, but the friendship needs to be a healthy one. But I just don't seem to be getting through to either of them, am I perhaps in the wrong.

Unfortunately the men I knew who behaved this way, did it so they'd latch on to future teen girlfriends.

One was a friend's married uncle and we naively thought it was cool then and felt grown up.
Didn't take long for him to sleep with some of our friends, all done in secret as he was married but found out way too late.

I'd talk to your son as if he was an adult - use the BILs insistence that he is against him. So rather than pushing the point that he's underage, discuss with him that his uncle clearly has a drink problem and why that makes drinking with him a bad idea. Discuss safeguarding issues and why BIL taking his 14 year old mates out on the piss is so problematic.
I don't want to sound alarmist, but a friend of mine in part became an alcoholic due to similar circumstances. His older male relatives took him out drinking as if he was a peer from his mid teens. By 17 or 18 it was clear he had an unhealthy relationship with alcohol and he was in rehab by his early 20s. Try to break this dynamic with your BIL as soon as poss.

I’ve seen enough generational alcoholism to recognise that very unfortunately your BIL isn’t quite the role model he could be. Your son looks up to him and is impressionable and there’s absolutely no way he should be dragging your son’s friends into this. I guarantee he will lose them if this continues. “Always looking for company” is a huge red flag - that’s what alcoholics do.

I used to go out drinking a lot at 17 with friends, back in the day when pubs were more sociable and cheaper!

Not at all responsible for your BIL though, he should be going out with his own friends and not encouraging your DS to do it. Xx