Originally Posted by Shadow5YA
I do wonder where Shinobu fits, since Koyomi seems to hide less from her than the other females. He doesn't tell Hitagi much about Mayoi. He had to put up a front with Tsubasa and pretend he was tough with his sisters. Suruga and Nadeko are even less informed.
With Shinobu, it seems that he doesn't really hide anything from her.
Make that he "can't" hide anything from her. And he knows it too. I don't think it's necessarily a bad thing to try to hide some details from other people so this doesn't really matter imo. If anything, Shinobu must fancy Koyomi really damn much or must be highly amused by his antics to put up with knowing everything about him lol.