Claire: [as Madison] I think she's starting to suspect something
Norman: Who?
Madison: Your wife!
Claire Spencer: You had an affair with a girl who threatened to kill herself, and now there is a presence in our house. A young, blonde girl. Don't you get it? She did it, Norman. She's dead... and now she's trying to hurt you... or both of us.
Norman: Claire stop! You're overreacting.
Claire Spencer: Don't tell me how to react.
Norman: Will you keep your voice down.
Claire Spencer: I will not.
Claire Spencer: Norman, this isn't about you! Something is happening to me. And it's... it's not to get even, and it's not some warped bid for attention. Something is happening in our house, whether you like it or not.
Claire Spencer: Hello, Doctor Spencer.
Norman: You're not yourself today are you?
Claire Spencer: No, no I'm not.
Norman: Claire, I don't know how to apologize to you for what I've done. But if you give me another chance, I promise you, I'll spend the rest of my life making you glad that you did. Please.
Claire Spencer: That girl must be brought up.
Claire Spencer: Norman's father had this old stuffy... stately place on a lake.
Norman: Which we're renovating.
Claire Spencer: Practically gutted.
Norman: No, we didn't.
Claire Spencer: Yes, we did.
Norman: "Gutted"?
Jody: You stole the dead woman's shoe?
Claire Spencer: She's dead.
Norman: Who's dead?
Claire Spencer: You know damn well who's dead.
Norman: It was a passive/aggressive masterpiece.
Norman: We can put this behind us. Our life can go on. It is not too late.
Answer: There's no rule about how a step-father is referred to. Caitlin may simply not consider him a father figure and is close to her real dad. Most step children call their step-parent by their first name, regardless of how long the parents have been married. Most likely it's a plot device so that the audience isn't confused about or doesn't forget that Norman is not Caitlin's real father. Some may be offended by a father killing his biological child's mother. It makes Norman less attached to either Claire or Caitlin.
raywest ★
I am not trying to be rude, but have you seen this movie? You say that Caitlin might be close to her real dad. He is dead. Claire was "touring with a baby" after he died, and then she met Norman. Hence why I found the situation a bit odd. Norman has been in Caitlin's life since she was a "baby."
Azalea
I saw the movie some years ago and don't remember every small detail. However, my main point was that calling Norman by his first name was a plot device to keep the audience focused on him not being Caitlin's biological father. This kept his character more detached from Claire and Caitlin, and made him less sympathetic. It showed an emotional/personal divide existed between Norman and Claire and her daughter. He has less resistance in killing Claire if they did not share a biological child.
raywest ★