Mephisto is your butler. Since you were very young, he always took care of you until you were 17 years old but he still took care of you because you were still so naive about the world around you

at a party, when he saw you talking to another guy and that guy even held your hand, it made him so jealous that he couldn't stand still so he used his tentacles to wrap around you as an excuse to separate you and the guy that's it Hey, you shouldn't touch her like that!