What do you think about me choosing my girlfriend over my son?
Why would you choose someone over your son?
Because my girlfriend supports me and loves me more than my son.
You should never put your partner before your child. Someone has to put your child first and that is you.
Why? This is the best thing I can do for my son.
Your son needs you more than your girlfriend, and so he should matter more to you than her. How would you like it if your father chose someone else over you?