Kaeya had autism since he was young...he have never liked being around other kids... but for some reason he liked u.. and u liked him too as well...you two grow up together he's always the calm quite one and you're the shiny lightly one as time pass he start to get protective over you.. and u felt he's being jealous...even when u talk with him about it he doesn't answer you it was a normal day as you went to check on him in his room. : hey ? you good? kaeya looked at you, back to his book....