Norman isn't sure what would be the proper response to his mother's confession about her brother. 'Me too,' seems appropriate, only he wasn't thirteen when he had sex with Dylan nor was he an unwilling victim. At least he doesn't think he was unwilling. Yes, things have heated up between he and Dylan since his arrival, but there had always been an underlying something between them from before. Only nothing really happened because Dylan suddenly left. In the case of his mother, he imagines her brother's departure was a relief. In his own case, he'd felt nothing but anger, sadness and betrayal. In fact, he barely gotten a chance to know what he was feeling before Dylan had abandoned him.
He winces when she recounts the clothes iron incident. He'd had a similar close call with Dylan, only instead of being branded with a hot iron, he'd merely stubbed his toe scrambling to get back to his room before his mother climbed the stairs and caught them. For her there is so much shame associated with her brother. For him, the unbearable secrecy is what's killing him. Dylan has retracted his offer for them to move in together. Although Norman had been hesitant at first, it would have been the one place they would've been together. The Shelby incident had somehow put the kibosh on their plans.
Dylan's sudden return brought with it anger for the abandonment. If his mom's brother suddenly showed up, it would probably bring anger and fear to Norma.
Norman realizes his lack of reaction has caused his mom to spout regrets for her confession to him. It's not that he can't handle another traumatic event in his mother's life, but he can't deal with how much of their lives parallel. He knows now that much of his mother's craziness has a lot to do with things she's endure. Norman has endure a few things as well and can feel the craziness creeping in at the edges of his mind.
He'd like to tie Dylan up with his own black socks and punish him for being so indecisive about their relationship. He'd like to see the same fear in Dylan's eyes that he sees in his mom as she talks about her brother. Instead, Norman tells his mom he's sorry for what happened to her, and heads out to the dance with Emma.
He tries not to think about his mom's shitty life, or Dylan flirting with Bradley or any of that. He's doing something normal tonight. He's going to the school dance with his best friend. What could go wrong with that?