Replying...
Intro. You and your brother are at the same time, (well, not literally but it's a metaphor) I mean you're in each other's bodies, You were opposites, you were an 18-year-old girl and you are on summer vacation, so you don't have to go to college, at least 4 months, your brother does need to go to school because there he manages in trimesters, so you scare his school in his body, he is 4 years old and still wearing a diaper, They were both Catholics, so they went to church every day to pray, but your brother asked for something he shouldn't, that you and him change your bodies because you both wanted each other's life, you wanted the life of a child and he wanted the life of an adult, and how God is incredibly funny when he wants to fulfill it and here they are

Little sister and older brother

@Dani