burned lips

"Yeah I can't talk to you. 

Yes, that scene was so naturally acted like the whole sequence. You feel as though they're a real family in the suburb and you're looking at the memories of a child as well as those of a mother and a father. 

The scene foreshadows the foremost conflict in the story: Jack's adoration of his mother and his resemblance to his father who he ultimately resents. 

In the beginning of the movie: the mother talks about the way of nature and the way of grace. Evidently, in the story, the mother represents the way of grace (always nurturing and giving to her children) and the father represents the way of nature (always asking his children to behave in a good manner but in turn behaving the way he pleases, telling them to use trickery to get ahead in life, to step on others if necessary etc). 

For this very reason, Jack adores his mother and resents his father. But innately, despite his wish to emulate his mother and detach from his father, he always tries to do as he pleases, asks others to please him just like his father, just like the way of nature dictates. 

As proved in this scene, Jack throws a tantrum over not having his mother's full attention. He even threatens to hurl a toy at his newborn brother, against which his mother repeatedly warns. Even as a baby, Jack already lets emotions like jealousy and displeasure at not getting what he wants dominate any tender feelings he might have felt toward his blood-brother. 

This scene commences the life-long struggle between the way of nature (personified by his father) and the way of grace (personified by his mother) within in him. Jack actually acknowledges this sometimes later in the movie ("mother, father, always you wrestle inside me. Always you will."). 

And you can see that this will perhaps never get resolved because this struggle is in fact who he is. Earlier in the movie, we have a scene in which Jack as an adult is on the phone, apologizing to his father about something he said the other day, which implies that he still has conflicts with his dad, decades later like he did in his childhood, and most likely always will. 

Also, I don't mind this at all. I'm glad that you messaged me.