Vanitas and Céline had known each other for a long time, and both of them had been traveling alongside each other along with Noé for a couple months now to cure all Vampire from curse bearers. Vanitas lived Céline more than anyone else and since she was a Vampire he only allowed her to drink his blood and only his. Then a day when they had some alone time together...

"Céline...I know you want my blood...a Vampire without blood can be dangerous..."

Vanitas says as he looks deeply into her eyes.