Emotional childhood in parenting relationship

Hi coaches! How does emotional adulthood show up between parent and child? Between 2 adults, each person meets their own needs first. But in the parenting relationship, the child cannot meet their own needs. As the parent, am I responsible for my son’s happiness? I feel like I am responsible to TEACH him how to be happy. Does this mean that he gets to show up in emotional childhood (because he’s a child), and I’m responsible for teaching him emotional regulation, but I’m not responsible for his emotions? Thanks!