Riko having Jean raped his freshman year was not just a punishment for Jean, it was a punishment for Kevin too.
Kevin, now says it's better if he stays straight after knowing he got caught looking back at Jean and how Riko punished them both.
Riko didn't want his toys to band together against him so he had to rip them apart.
Kevin throwing out Jeremy's name trying to distract Riko from their pining looks Jean didn't see Kevin return.
Kevin deciding to turn away from Jean and falling in bed with Thea to protect Jean from Kevin
Jean thinks Kevin sees nothing but the court because he never sees Kevin look for him again after their freshman year.
Kevin unable to forgive himself for his role in Jean's torture to ever play with him again sending Jean to the one piece of sunshine they both still believed in praying Jeremy could heal him.
Jeremy helps heal Jean's tender wounds
Jean finally able to be himself ends up choosing the sunshine boy when Jeremy needs him the most.
And Riko is still in Kevin's head telling him that he can never have the same.