@Exos just going off of the fact his niece couldn't get in couldn't be her, his sister is at home making sure his niece gets back home safely. And not even mentioning the fact that figure and hairstyle belongs to character introduced several chapters ago "Kageneko", yknow the femboy that they tried cross dressing as a maid a few chapters ago? I don't know how you came up with the idea with was gonna be a incest scene but the clues are there.