Who's the asshole?

Yesterday I went to meet an old friend with S at TGIF.
It was to be a fun evening.

In the middle of the conversation, in a light hearted fashion, she called him an asshole, and told him to stop mistreating me, not once, not twice, but a number of times and in a number of ways.
I saw a hurt expression flash across his face for a second and then his face compose.

I have known this friend, lets call her N, since class 7th. We've been relatively close through the years, only losing touch in the recent past, simply because of her going to UK etc. Therefore, I can safely say that today we are not that close, that she be in a posiiton to guide me or S about how we should be solving our problems.

When me and S broke up, it was common knowledge ( was it not?) and my being hurt was on public display as well... coz that's me... and I need shoulderSSS to cry on.
He, on the other hand is the quiet one. Throwing himself into work to drown his sorrows, rather than talking to people. So, getting gyan on how to run his relationship, specially from my friends, didnt obviously go down very well with him.

Assuming that breakups and patch ups happen... assuming fights happen... assuming people talk to people when they're hurt... was I completely wrong in pouring my heart out to my friends? to u?
Does that mean that every word which I speak is carved in gold, and that now Ive created an impression of the man I love which might be partially incorrect? simply because its only my side of the story?

Keeping my dilemmas aside, why would a friend of mine deliberately try to belittle my boy friend in public? Wouldnt a friend know that it would be humiliating for him and damaging to my relationship? Wouldnt it be hurting me indirectly? Is that really a true friend?

Right now, I'm very hurt.

Hurt because I dont know whom to trust.
Hurt because I dont know the definition of friendship
Hurt because people can be unthinking.
Hurt because Ive hurt S, and I love him.
Hurt because no amount of apologies are likely to change his new found view that I actually hate him in my heart of hearts and all Ive done over the past few months is said nasty things about him to the world.

Who's the asshole? Me? Him? or friends?