Hello @iskawrites, my regards, thank you very much for the comment.
What happened with Joaquin that day, is that he was humiliated in public more than once by her.
On the other hand, I really don't know how their personal relationship was, but they were as different as the sun and the moon.
After the party, I didn't ask about Karla anymore, there were no complaints or anything and we all let life go on.
A few weeks later, Joaquin was dating another girl, whom he married and they have been together for years.
My regards.