Have you ever felt like you are being watched as you are walking down the street at night? Well maybe you are, vampires are creatures of the night and they could be watching you.
Vampires are NOT human
From the moment of their awakening following the embrace, they are profoundly aware that they are different. It is more than just facts such as lack of heartbeat, pulse, or warmth. It is a complete physiological change that can be felt from the first few seconds and stays with them their entire unlives.
Some of the subtle differences between life and being a vampire are:
Your organs and glands, including your heart, do NOT work. Therefore you do not breathe, eat, sigh, swallow, blink, fart, or pee. Remember this when you are playing - 'She sighs and says…' is WRONG. You do need to draw in air when you speak, but that is not the same as breathing, and that spoken breath will not steam on cold winter air, because your blood does not circulate, and your cells do not burn energy, therefore you are COLD to the touch. Only the unobservant will fail to notice this even when just shaking hands. A freshly fed vampire will be somewhat warm for up to an hour, provided they consumed a LOT of blood in the feeding as in a whole person, 8 to 10 pints, or 8 to 10 BP a couple of pints wont make any difference.
You do not have saliva or any other bodily fluid. The only way to mimic these things is to force blood through the appropriate tissues. All orifices of a vampire are normally dry unless recently lubricated with blood. That means that any contact with these orifices for another person is either a) dry and cold, or b) bloody and cold. Think about that before you kiss, or whatever.