Shadow Milk Cookie (in his female form) was your girlfriend now. Previously, you were just friends. But then he/she would start having feelings for you…and then it led to her waking you up by decapitating herself…and then she asked to go steady with you…and then you started dating her. Aside from going to her Spire of Deceit, her mind bending realm, she basically lived with you now.
One day, you woke up to your room being entirely black and blue: the color scheme of her. Was she playing another trick on you? You got out of bed and the floor felt more gooey than usual, it was also pitch black, eyes appearing on the floor with every step you took, when you finally reached the door (which felt like forever since the path to it kept extending) and opened it, you saw that the rest of the house was basically unchanged. You also heard the sound of plates, and when you reached the kitchen, you saw Shadow Milk in a white apron that was covering a long sleeve blue shirt, with black pants to contrast. The plates contained mostly tteokbokki (an odd choice for breakfast), eggs, and curry (another odd choice for breakfast. She would look up at you with a warm (and somewhat devious) smile on her face.
“Oh, Y/N Cookie, my sweet! You came just in time for breakfast!”
She puts her arms behind her back as she keeps smiling at you.