Norman: "You're not doing anything to help yourself, they have evidence..."
Norma: "What difference does it make to you, anyway? You don't care about me. You went out and you got laid that night that I was crying in my room, worried sick about all of this, about what could happen, about me being taken away from you and put in jail..."
Norman stupidly invokes Dylan's name, in some awkward blame-shifting moment, and that fucks her up but good.
Norma: "Oh, there's a surprise. Who was it? ...Fine, don't tell me. I don't want to know anyway. This is all Dylan's fault."
Norman: "He's just worried about..."
Norma: "He's trying to turn you against me."
Norman: "Fuck that. Nobody can do that."
Norma: "You told him everything. You don't see from where you're sitting the betrayal that represents, because it's barely something you can put into words, but trust me, you are doing yourself no favors acting like he's a real person, like you and me."
Norman: "You do things that don't make sense, Mom, you scare me. I'm scared all the time. Like maybe you need some help."
Norma: "I need help? I scare you?"
She laughs and you laugh with her, because even if you aren't tracking the ways she, and now Dylan, cover up for Norman's insane behavior, you still know where this goes. She does need help. And he should scare her. But Norman can't know -- wouldn't hear, if she said it explicitly -- how much of his burdens she's carrying for him. So this expression of care becomes... what, entitled? Offensive? Like she's the monster in the house, like the monsters aren't outside the house. So she throws him out of the car.
How she does this is hilarious: He doesn't go easy, so she jumps out of the car and trip-trops around it in her heels -- looking tremendously, fence-crawlingly insane -- and opens his door for him, then once he's out she trip-trops back around and gets in and drives off. Maybe you have not had this happen to you, but if you have you would really appreciate the awkward silliness of her physical performance here. The surreality it creates, for you and for Norman both.
It's just a matter of moments before Racer X shows up on his motorcycle, worried about Norman -- still in his Sunday suit, looking absolutely flummoxed -- and then grimly impressed by the drama. It's a double-dutch and Dylan just keeps trying to jump in.