That doesn't mean you had to drink it, take pics of you drinking it, or post the pics if you drinking online.

it just says the pics were on Facebook, not on their personal account. for all we know a coworkers snapped a pick and posted it, then the boss saw.

His party . Your face book pictures. watch what you post.

Even though he supplied it, you had the choice not to drink it

Even if it was his party and he supplied the booze, if you're underage, you shouldn't have been drinking it. You also shouldn't have posted pictures of you drinking while underage on the Internet, that was really stupid. He's completely right in not wanting his business to have that kind of reputation.

Damn hypocrite! Tell the cops and get him put in jail for providing alcohol to a minor.

Did he force you to drink it?

Just because there is a hole doesn't mean you should put your dick in it.... Same logic for this.

Just because he supplied the alcohol, if you're underage, you're underage. It's still inappropriate whether the temptation is there or not and clearly you weren't responsible enough to make the right decision, regardless of whether or not your job was riding on it. You deserved it.

Were you the idiot that posted them on Facebook or someone else? Either way there are consequences for all actions.