I think it depends on the situation. Ian was being extremely self pitiable and proved how low he thought of himself. Nicholas' slap worked as a "slap of reality" that made him realise that what he was saying was not right at all to his friend, the person who knew he was talented and who knew his character. His comment WAS out of jealousy but his intentions were obviously pure, since he was only trying to make his friend chase his career. If he was sooo bad he wouldn't prompt Ian to live up to his potential. And leaving in dissapointment, that might change Ian's mind. He knows that, so yeah, seems like a really good honest friend to me.
I understand what you’re saying, I do believe he was the little push Ian needed (he had doubts before Nicholas and he will continue to have doubts even when Nicholas leaves) but as his friend he shouldn’t be close minded and should try to put himself in Ian’s shoes. That comment and that slap really showed me that he is a jealous person and really wants Ian’s talents. The reason why Nicholas slapped Ian isn’t because he wants him to realize Raymond isnt good for him, it’s because Ian said he’d choose Raymond over painting and Nicholas got mad cause he thought that was “demeaning” Nicholas dream for painting. that slap wasn’t a “wake of reality” for me, it was a “how dare you insult my love for painting like that” And then said that unnecessary comment where he’d want Ian’s HORRIFIC past, and then to top it all off, left Ian when Ian needed him most. Again I get what you’re saying, and the stuff he said in the beginning to Ian made me really happy because Ian may finally understand his worth...then he slapped him and demeaned his trauma . I’m pretty sure we are just gonna have to agree to disagree on his character.
I'm disappointed in Nicholas, he doesn't have the right to slap Ian and say those harsh words. Ian is not a good painter because of his traumatic past. He was talented to begin with.