Having trouble finding a specific yaoi manga.

HELP!! I'm looking for a side story inside a yaoi series. The side story is of a Uke with light hair summoning a demon who is the Seme he has black hair and batwings tattooed on his back. I think it's by the same author as the one who wrote Honto Yajuu! But I could be wrong. It's been awhile since I've read it but I know it's not the yaoi Kimi To Kore Kara by that same author. The one I'm looking for is a small side story, I'm having trouble finding it, does anyone know what I'm talking about? Thank you for any help