May I suggest... Hot Older Brother Levi, Potterverse? Hufflepuff Eren meets a fellow Hufflepuff, Isabel, who takes him to meet her friends, who she kinda didn't mention were Slytherins, Levi and Farlan.
OMG French Levi and Jean. Perfection. But Eren, the preciousness that he is, is believed to be German. what if while Eren melts at Jean and Levi speaking French, both Jean and Levi maybe kinda have a bit of a thing for Eren speaking German?