Shoki-gai kara Tabidatanai Yuusha no Harem Life ~Yuusha-sama, Konpura-teki ni Auto desu!~ - Vol. 1 Ch. 3

[MangaDex]

 

[LaurielLevane]

The ninja must be playing dumb since i don't believe she doesn't know about the others.

 

[name_go_here]

I wouldn't be surprised if all 3 of them knew and they have an agreement to respect each others' private time; with the whole "not let anyone know" bit as an agreement to keep the poly out of public eyes.

 

[HaremIsIdealButNotPragmatic]

"I doubt Goblin Slayer would be able to detect the Goblins disguised as humans..."