seungpyo gets super angry just as @Saikopsycho said and then ryu jaemin asked oh to have sex with him, if that meant getting back with him in whatevre it was between them, to which seungpyo agrees. his brother was out apparently and they meet up on weekend, do the business, jaemin realizes he likes him and i think he tells him too at that very moment. so they start dating (▰˘◡˘▰). so no angst or avoiding arcs!!!

So basically in the novel, ryu jaemin sees this post which said that "someone confessed to the topper just to distract them and bring them down from their rankings" or smth between the lines. since they had their finals (or some other exam i dont rem sorry) upcoming, ryu jaemin took it as if seung pyo made this plan to distract him from studying and shit, but oh's feelings are genuine you guys ╥﹏╥