I mean it's more like, flirt, snark, flirt, "should you really be hanging out with a high school girl?" Then they slowly regain their powers and Yato finds out she's a ghost, probably.

Also she wants bento boxes and bentos are made with love YOU CAN'T BUY A MOTHER'S LOVE but Yuuko's mom is dead in this au so this suddenly got 2real

The point is, she'll pay him to hang out with her because she's sad and lonely.