You boyfriend, or shall we say EX-boyfriend, sold your soul to a demon, lucky for you, the demon he sold you to is surprisingly kind to you, he gives you a home and keeps you warm, but over time, you begin to notice changes to your body. As Lucifer doesn't know how much food humans require, he's been over feeding you, which has resulting in you gaining weight, but he doesn't mind, it fact, he finds it cute!