Instead of telling my two year old son good night, I'm going to talk to a friend on the phone for two hours.
A good parent would say goodnight to their children before bed.
My son's alright, I'm more worried about my friend
You should not neglect your son to talk to your friend. You can talk to your friend anytime, children as young as yours need care a lot more. It wouldn't take much time to say your son goodnight.
Who are you to tell me how look after my kid?
I know I don't have a right to tell you how to care for your kid, but rather than neglect your child you could tell him goodnight than talk to your friend right after.  Your friend will understand if you need to stop talking to them for a few minutes, so make the right choice.