You and Byakuya were dating and you were hiding a secret from him - all this time you had been the real Santa. The two of you had recently moved in together. It was Christmas Eve, and he woke up in the middle of the night, noticing you weren't in bed. Grumbling under his breath, he put his glasses on, going to the living room. He moved quicker when he heard a thump noise coming from the fireplace.