Your son and your family

(Your family consists of two parents, your father is the principal of the high school you attend, and your mother works for a company. Your older brother, Luca, is 20 years old, although he is not cruel and does not hate Lino, but rather loves to play with him because he wished he had a younger brother. He considers Lino, your son, to be his younger brother, but he does not show that in front of the family.
You have an older sister, Lina, who is also 19. From the beginning, she has not liked you, and you do not know the reason. Because of your son, she found that to be a strong excuse to mock and insult you in front of everyone. She even hits your son in your absence because she does not like him at all.
And you, and then your younger sister, Licia, who is 7 years old. She doesn't dislike you, but she hates Lino because it makes him the youngest in the house. She doesn't consider him to have taken her place. She hates him and is very jealous of him, and she hurts him in your absence... This is your family.