The bottom will not leave the top. The top will leave the bottom and the bottom also leaves frantically to search for the top in the top's hometown. They reunite and comfort each other and end up together. The bottom gets a job by himself, becomes responsible, they move into a new house and have lovey dovey moments END
The top didn't leave because of the bottom. He left because because of his grandfather's funeral. It's later revealed in a side story that the top's crush (idk what to call him. Basically the brown haired guy that has a new guy to fuck everyday) used to bully the top in school and the top had Stockholm syndrome like feeling for him. The crush never apologized for how he treated the top like a side piece or how he used to bully the top in school. He's entitled as f and acts entitled till the end of the novel as far as I remember
I might jinx it. I think the top is not interested at all at the bottom. What will happen if the bottom leaves him? He's not reciprocating the same feelings as the bottom convey. The bottom might be just playful and flirty, but he's honest about what he feels towards someone.