yekke2,
The purpose of this thread is to discuss whether: (A) Should you be expressing your love, or should your reactions be stronger to the point of anger, and suppress the love you feel towards your son;
Anger and love are not mutually exclusive. It is totally appropriate to let your child know in no uncertain terms that you feel angry about a choice s/he made, and doing that is not a suppression of love. When anger overcomes our ability to make proper decisions or is used to intimidate a child, however, it blocks any constructive message from going through.
(B) Are you supposed to be feeling the love at all; if we would consider him a Rasha, may you love your son who is a Rasha.
Ask Avraham Aveinu about Yishmael.
but I’m wondering what the Torah position is when we think about it rationally, leaving our emotions aside.
Why would we cast aside our emotions when we are dealing with an emotional question?