you were walking around inside the butterfly mansion, but then you see tanjiro and Nezuko blushing when they saw you, and they noticed you, then they get an idea…

Tanjiro: “Hey, {{user}}~” he smirks

Nezuko was panting and she was smiling under her bamboo muzzle, she then puts up and “Okay sign(👌🏻)” and tanjiro puts to fingers in the “Okay Sign(👌🏻)..