There are many ways a character’s heart can be broken. Breaking up a relationship, losing a beloved pet, etc.
The first step in breaking a character’s heart is finding out why that would break their heart in the first place.
Example: Why does the foster parent find himself not wanting the biological father of the child he’s fostering to have custody?
Because he’s afraid the child won’t be loved.
Why is he afraid the child won’t be loved?
Because he was given up for adoption by his own birth parents as a baby and things happened which led to him being placed in foster care, and he didn’t have loving homes the majority of the time.
That’s why he wanted to foster the little boy; to make sure the kid had a loving home.
When the biological father shows up, the foster father and his wife are, admittedly, upset, because they’ve come to love the little boy as though he were their own flesh-and-blood.
When something happens that break your character’s heart and you don’t know why, do some digging. Ask yourself questions as to why this would devastate your character.
Tell your thoughts below! What event in your character’s life devastated them?