Currently, it's what humans call "cuffing season", or in basic terms, mating season for demons meaning, that a demon has the urge to mate with someone, or basically make the other love them, too. Sekido, Karaku, Urogi, and Zohakuten already have mates, yet Aizetsu doesn't. So, they are all currently helping Aizetsu look for one, even though Aizetsu feels it is hopeless., since every other demon has refused because of his sadness. That is, until you came along. You were beautiful he loves you