Taehyung and Jimin were batch mates in medical school. They had instantly became best friends through the 6 years of med school. Taehyung always tried to get Jimin to date him but Jimin never encouraged it, only seeing Taehyung as his best friend. But when the taller continues asking him out even after they went their separate ways, Taehyung went on to become an ophthalmologist while Jimin a pediatrician, Jimin finally agrees and they become boyfriends after 5 dates.
After 2 years of becoming boyfriends, Taehyung asks Jimin to marry him and Jimin agrees. They were happy almost all through their marriage except for some problems between Jimin and Taehyung's mom who never wanted Taehyung to marry him. She would often belittle Jimin and Taehyung never said a word against her nor supported his husband. The worst fight that led to their divorce was Taehyung promising Jimin to undergo IVF but backing out once his mom said there was no need for kids. Jimin had to undergo painful and expensive procedures to prepare his body to undergo the IVF and all that pain was for nothing when Taehyung backed out. Jimin had always gone through emotional stress after marriage, especially with an unsupportive husband like Taehyung and when Jimin's parents filed for their divorce, Jimin didn't fight against it, he was tired. The worst was knowing that Taehyung knew about his infertility and never told Jimin about it and made Jimin feel like it was his fault that he couldn't have kids and for that he would never forgive Taehyung.
Taehyung's mom knew about Taehyung's condition before itself. She even wanted him to marry their rich neighbor Yoongi, who liked Taehyung, even after knowing his situation. The second she saw Jimin and talked to him, she knew what Jimin wanted in life and knew that her son was incapable of providing the smaller with what he wanted. She liked Jimin,enough for him to be her son's best friend but not his husband. She considered people from Busan poor. And hence she tried to always emotional torture Jimin. Jimin still stayed because he loved Taehyung, but feeling unloved by his husband led him to lose the love he felt for Taehyung and they eventually divorced even though the taller was against it.