Sensei forced him to give him fellatio so that Nanao-san and Kuon will be together.
He acted as the bad guy for the sake of Nanao-san. (I think, not sure though)
Yeah, I wonder that too.
I wanna know about that too.And I don't understand why this is marked as annoying even though it is a legit question ╮(￣▽￣)╭
Cause the sensei was also obsessed with Nanao and forced him to do it when he realized Nanao had chosen Kuon and not him. Why they keep overlooking how truly despicable the sensei is, I cannot understand.
He gave sensei fellatio because? ??