Girls, would this upset you? Watch
You don't really have a right to be all upset and righteous about it. If you've got yourself into such a drunk state that you're vomiting in public, you've sort of lost the right to be indignant. Of course people will laugh at you, because you've embarrassed yourself.
EDIT: I toyed with 'we' here, instead of 'us'. I didn't much like it.
But I think what's far more important than being upset is realising that your boyfriend clearly sounds like an immature low value doouse. Are you 16 -18? if so maybe that explains why you don't see the obvious etc, if your in your 20's surely you must be looking for a true man by now? And not someone worthless like that.
Catch yourself on.
If you were sick in public after a night out, and your boyfriend found it funny and commented about it on a Facebook feed (with friends) would you be upset? Is that immature?
Your boyfriend is allowed to have his own opinion, often people will not view things the same way that you do, however him posting it on social media is immature because it shows a lack of empathy and understanding of the situation. I only say that it is immature because in my experience those with less knowledge and understanding don't realize the impact of their actions.
As he is your boyfriend he didn't intentionally do it to cause harm and to make you feel uncomfortable / embarrassed, he probably just misread the situation.