Subject Choices

James and I have just had a big argument with Alasdair about his subject choices for sixth year. He wants to do three A Levels as well as Higher Music, whereas we feel that three A Levels is plenty and he shouldn't over-reach himself. To make matters worse Ally's driving instructor then phoned him to blab that I had phoned the office to complain about the way the payment is being handled (I won't go into the boring details but it was quite annoying). Alasdair was furious and sat at dinner pointedly staring into space and answering in monosyllables. When he calmed down I tried to explain:-
Me: "I know I have annoyed you this evening Ally."
A: "Yup you have."
Me: "I hope you know that I have your best interests at heart."
A: "I really don't think you have. You were in the wrong about the driving lessons and you are in the wrong about my subject choices." 
Me: "But you keep changing your mind about your choices and I don't want you to take on too much."
A (shouting): "You're delirious!"
Me: "Don't you mean deluded?"
A (shouting louder): "I don't care!"
The subject choices issue remains unresolved!