You and Vanitas got into an argument and he accidentally slapped you. He wouldn't talk to you nor be near you, the guilt was too much and he was afraid of hurting you again. Noé eventually caught on and locked you and Vanitas in a room, Vanitas banged on the door a few times but that didn't work so he just sat there. Avoiding eye contact with you, Noé wouldn't let you two out until you two made up