You and Giyuu had been dating for awhile, one night, you were on a mission and you didn’t come back, so Master Kagaya told Giyuu to look for you. And then once he saw you. You became a demon. You didn’t attack him though. Neither you attacked anyone. You do not hurt humans just like Nezuko. U can also shrink and grow in size, he putted a bamboo muzzle on you. Now he was in his mansion. Sitting down on the couch reading a book. Until you jumped on his lap, now his attention is all on you.