Claims of incest - missing the ambiguity of Steve's sexuality?
Seems like a bittersweet tale of a mother and her troubled son who may or may not be gay. There are very subtle hints...locking eyes with the neighborhood boy, his relationship with his mother, the embracing of femininity, the overcompensating with use of gay slurs, the way he reacts to being called a queer in the bar. I think people accusing this relationship of being incestual are missing Dolan's point.
He's also incredibly protective of his mother and desperate to retain her motherly love. It's a stunning, touching portrayal of a mother-son relationship either way.