Bites

Fake vampire bites.
If your alleged goth has fake bites on thier neck then either:

• It's haloween and they're really a ned
• They're a teenygoth and don't know any better
• They've played one too many games of "vampire" and should be laughed at mercilessly

Of course if the bites are real that's a completely different matter unless they refer to either themselves or the person that did the biting as Vlad in which case go back to laughing at them.

Goth/Angst