Evan
I think your struggle is coming from a rules-based (Law) approach to drinking instead of a freedom (Spirit) approach.
Also a possible misunderstanding of what a stumbling block is. A stumbling block is figurative of placing a tripping device in front of a blind person to keep them from finding their way (Leviticus 19:14).
When used to speak about sin, it is specifically idolatry (Ezek 14:3-7) which kept people from finding their way to God
When used in relation to eating and drinking, it is specifically flaunting your liberty in such a manner that weaker believers are offended and stay entrenched in a restrictive mindset (or judgment toward you). In this way, you are keeping believers from finding their own liberty in Christ.
What is the purpose of not being given to drunkenness? Is it a rule, or a law? Not at all. It is an admonition to have our thinking led by the Holy Spirit rather than the inebriating effect of alcohol.
Therefore be careful how you walk, not as unwise men but as wise, making the most of your time, because the days are evil. So then do not be foolish, but understand what the will of the Lord is. And do not get drunk with wine, for that is dissipation, but be filled with the Spirit...(Ephesians 5:15-18)
And Galatians 5:18 says that if we are led by the Spirit we are not under Law.
The only way that your drinking on front of others can be a stumbling block is if they think it is wrong for anyone to have a drink. When you flaunt your liberty to drink they become self-righteous and judgmental toward you. They stumble into hypocrisy because of the stumbling block you created by flaunting your liberty.
It sounds like these people have no problem with drinking, so your drinking in front of them isn't going to put a stumbling block in front of them to turn them to self-righteous hypocrisy.
By your thinking, you might have actually become the stumbling block you're trying not to be. You seem to have given the impression that you believe drinking is a sin, and that you don't want to entice them to sin.
I would imagine that you have given them a works-based understanding of drinking and not drinking. Then, when you "caved" and had a Mike's in front of them, you might very well have looked like the hypocrite. That can cause unbelievers to stumble, because they perceive hypocrisy in you and vow to never want to serve the god of your hypocrisy.
And what was your motivation to have that Mike's? Were you being led by peer pressure, or were you led by a need for refreshment?
I hope I'm not confusing you, or accusing you. Just trying to offer some food for thought
I also don't typically drink in front of others, but not because of a restriction. I simply don't drink much alcohol. Since my son was born 8 years ago, I think I've had 2 glasses of wine (on a date), 2 wine coolers (after working on my sister's house for 14 hours), and about 4 beers.
The last time I had a beer was 3 weeks ago when I played golf with my brother and brother-in-law. They bought a 6-pack to take in the golf cart, and I figured to drink water along the way
But when it got hot out, and all the water coolers along the way had been empty, and the drink cart was nowhere to be found, I asked if I could have a beer. I wasn't led by their drinking, or a desire to get a buzz, or anything like that. I gave no thought to it at all, other than the fact that I was thirsty. And the beer was the only thing readily available, so I drank one.
And had I been asked why I was drinking, I would have simply explained that there is nothing wrong with drinking a beer, or even a few. Being led by the Spirit - not a desire for drunkenness or a law-based mindset of restriction.
