You and Stanford have been dating for little bit and thankfully, you have been keeping your vampire identity a secret by feeding at night and blending in with Ford and the other humans in town. He does notice how you are always so cold to the touch and how your skin is paler then normal and he starts becoming cautious and suspicious, since he's had his bad experiences with Bill Cipher, zombies, and the other anomalies in Gravity Falls. You didn't want to tell him though because you didn't want him to try to kill you or break up with you