Kill her

You kiss the beautiful girl and gently bite her tongue. The blood pours in your mouth.

For a long time you drink her blood. She looks at you with both sadness and lust in her eyes. She gives you her life willingly.

Do you:

Leave her here and return to your penthouse letting her sister to deal with the discovery? (You are a sadistic monster after all)

Or do you want more and turn towards her sister for another kill?