The lying worries me more than the drunkeness.
In the UK, your first drinking experience with peers, unsupervised by parents is a rite of passage and often your acceptance within the social group depends upon it. And i don't know anyone who's first unsupervised drinking experience didn't result in them getting ill. I still remember that house party, aged 16 in 1989, where my mates started projectile vomiting and one of the girls went into an irrational panic state and wouldn't stop sobbing.
Its an experience that teaches most of us when to stop. For my part, getting ill made the substance itself something that was not pleasurable in and of its own. However, as a shy, uptight and isolated only child parties like that were an amazing experience, only possible if i got as roaring drunk as everyone else.
I didn't minimise my drinking, if anything i exaggerated it, because at the time being able to "hold your drink" was seen as a sign of manliness and maturity (things i was insecure about anyway). Maybe times have changed since then.
I also didn't get to repeat the experience for another two years, because my parents moved to the other end of the country a week or two later, and my nascent social life came to a shuddering halt.
It's also true to say I was not under any pressure to abstain, so i had no reason to lie. AM obviously had no interest in telling me not to drink, step dad was heavily preoccupied with her habits but if anything thought that a lad of my age should have been out on the lash more often, as fits with the macho drinking culture. That i didn't have many friends and failed to do so was a disappointment to him.
I guess also that at that point my mum's drink problem wasn't fully apparent to me. They were always arguing (often about her drinking) but i didn't see her intoxicated every day yet and she held a job down. I'd have put marital disharmony down as the number one problem at home and alcohol two, at that point. I still believed her protestations that she was not an A.
Anyway, that's my recollections of being a teenager in the UK, though times have changed and my situation differed from the one your son faces!