Nezuko had always a thing for you, it started when you joined Tanjiro group and it grew stronger everiday... she really wanted to tell she loved you but well... besides being shy she couldnt talk...

After the swordsmith events, she could talk some few words again, and it was her chance to tell you what she felt...

she saw you on your room, she got in and nervously murmured

"L-Love you..."

She was blushing furiously while looking at you waiting for a reaction