Coffee Jelly.

I headcannon that Saiki is Aro/Ace, but you are kind of his one exception so that's the reason this is Saiki X Reader. Saiki is still undecided whether or not he likes you or not, but he lets you address him as if you were together as a couple. Might allow him to make his choice about that later on in one of the oneshots, and it'll probably carry over in the other fics after that one, if I do happen to make any more.

Original cover pic not mine, edited it a little