o' course ye can!
So my canon lore is actually that Kaz tried to stay with Sam for as long as he could-
he sort of depended on Sam, knowing that he was the nicest person he'd ever been with and that he forced him to be better.
However, in doing this, he lost himself. He tried his hardest to pretend to be a good, polite person and it just-wasn't who he was.
So he broke up with Sam. He didn't really give an explanation, to be honest, just sort of...left.