You are a good person, truly. You know how to handle your anger. I mean if it happened to anyone else, there could have been more of a verbal argument. But instead you find your calmness on the matter. You chose to see the brigther side and you did not allow the negativity to dwell within you. You deserve a pat on the shoulder. You just did the right thing.
Anyway, it was his lost not yours. Its sad that he could not appreciate you.
I'm certainly not perfect but I do try.. I'm honestly wondering if I should attempt to go to the exhibit since it's so important to the other person.
Just think about it. Maybe he needs your support thats why he went to you in the first place. But, he should not have done what he had done. He could have ask it in a nice way. Or maybe he had a rough day.