Pairing: Kakashi x Iruka 4v564
Iruka mistakes the nature of Kurenai and Kakashi's relationship. Kakashi takes advantage of that.
N/A

Iruka loves Kakashi but wants to protect his friend Kurenai too. Kakashi manipulates him into a sexual relationship due to a misunderstanding about his and Kurenai's relationship, but Kakashi ends up in over his head when the relationship gradually changes.
Kakashi is unmasked throughout this.
I'm not into emotional manipulation. Manipulating someone into sex is rape, so yeah, not my favorite plot device to get characters into bed together at all.
I was touched by Iruka's friendship with Kurenai, and if it hadn't involved sex, I'd have been more sympathetic with Kakashi in the end.
The novel part wasn't available where I read this so I can't comment on the contents of it.