Hello Dangerranger & welcome
Alcohol is often drunk regularly and in large amounts by young people. Here in the UK, it's legal to drink at 18, so I hadn't realised that it was illegal for your girlfriend to do so. Are you in the USA?
I don't drink much, but I will have the occasional sherry or glass of wine ~ as will many people. It's pretty harmless for most people to do that. However, for young girls to drink until they pass out, or wet themselves in the street, is pretty disgusting, in my opinion, and very dangerous too ~ in many ways.
So, what is it in your case?
Are you worried that she might drink so much, that she will show herself up ~ ie say stupid things, be sick, wet herself in public, etc?
Are you concerned that she might drink so much, that she will become seriously ill, by damaging her liver, or poisoning her blood?
Are you concerned that she could put herself in danger with strange men who might attack her ~ or worse?
Or get so drunk that she falls under a vehicle?
Are you worried that she might drink so much, that she will go off with another man?
Is it simply the case that you just become outraged when people break the law?
Or do you feel that she is beyond your 'control' when she is out with others ~ especially under the influence of drink?
It would make sense, if your girlfriend was out, getting blind drunk, and putting herself in danger, without you even being there to look out for her / look after her.
But if she is in control of her senses and only having one or two drinks in a safe environment, it's a different matter.
I'm glad that you have given up smoking drugs. Overuse of any drugs must be bad, unless taken medicinally, in my opinion, because of the harm they can do ~ and this includes alcohol and cigarettes. Certainly cannabis is seen as 'more' illegal than alcohol, because she will be allowed to drink soon, whereas cannabis is not legal at all.
Why do you think you get upset about this?
Is it because you dont drink, and you want her to be the same as you?
~ That's possible. I think that we all would like our psrtners to have the same moral standards, etc, as we do.
Yet you are not against cannabis ~ how would you feel if she took that?
Is it that you dislike partying and hate to think that that she is having fun while you are not?
~ That's possible, too. When we have a partner, we tend to want to share the good times, not be on the outside, hearing that our 'other half' is enjoying themselves elsewhere & with others.
So, why are you so much against alcohol, but not against cannabis?
Why don't you want to go out and enjoy yourself with your girlfriend?
Are you worried that she might go off with another boy?
Does she get very, very drunk?
If so, does she understand the dangers?
How long have you been together?
Can you change, so that you either join her at the parties (if you get the chance) or give her the freedom to go with friends without questioning her?
Do you talk about this sort of thing and try to compromise?