Seikishi ni Natta kedo Danchou no Oppai ga Sugosugite Kokoro ga Kiyomerarenai - Vol. 3 Ch. 23

[Umesan]

Well if you guys wanted a preview on Myu's real identity... There it is. That fencing sword was used by another character earlier in the series

 

[Phaaze]

The ultimate power against a succubus queen, being a virgin. That comedic shocked face at that revelation.

Looks like the succubi in this story can't sniff out virgins, like others I've read, where they're favored over non-virgins.
That revelation was funny to me because this.