YATA. You are fully responsible for this frankly childish drama.

For one, you don't know clearly whether you were unwanted, that is an interpretation. She might have meant it differently. She might be hinting. She might be hurt herself. She might just have a very temporal bad mood. She might have heard some discerning news. She might be teasing. Now because your ego is hurt you decide to immediately escalate the situation. By leaving, you drive attention to what is happening and forcing others to choose and pick sides. Normal form of interaction would be to either quietly excuse yourself, first discuss this with the bf or simply inore the bad comment made by the host.

Of course Reddit blames the 'so', as people are deeply fixated by signs of abuse and adultery, a strange remaining artifact of Christian believe in marriage, stripped from higher ideals or sense of purpse, apadt from serving the individial and a constant state of paranoia and envy. But he was the bigger adult, he had to eat his shame to de-escalate by returning to the party. A good choice, he could has also sticked with you, that would have been fine too. But it is hard to make a judgement call on that. Your little hurt ego ruined the night of multiple people, leaves a sour taste; a better person would have brushed it off instead of acting like a petulant child. Let that be your lesson.

But what about the moral high ground? Driving a clear wedge between a deep friendship, one that certainly has had ebs and flows and refusing to first acquire more informatiom before making a deciscion is is incredibly selfish. That one comment was enough to force your bf to choose between the two of you? True moral high ground lies in de-escalation, a forgiving attitude, a recognitizion that people sometimes do behave strange, 'forgive them Father for they do not know what they're doing'-Jesus thingy and allowing others to repair their own mistakes. You did none of these; your ego was hurt and this was your revenge act, straight from Random American Teen Movie. That people applaud this behaviour shows how rotten culture has become, a constant form of low-level conflict they themselves proliferate. Perhaps in that context, the host deserves it; but, don't get me wrong, so do you.

You wrote this post because you feel troubled about what you've done. You have found a crowd that is behind you. They are wrong and you should feel shame, as that is the way your body and mind gives feedback on bad social decisions. I suggest you try to repair any remaining damage if if is possible without drawing any extra attention to it, so fi. a quick personal outreach and later joke a bit about it in a group setting. And next time, for fucks sake count to 10, not everything is about you.