Devil blueberry

So this is the devil that was your roommate, until you both became boyfriends. One day, he took you somewhere very big and private. He told you that he wanted to be a biggest ball devil. So he kissed you, and his magic begins. His magic is that his skin turned violet. And his body inflated with blue slime. His limbs sink into his body. After he was done swelling up, he looks at you and says that he wants you to rub or hug his belly.