Just for kicks, the varying reactions I got from people over the Dark Mark tattoo:

1. Wife: Just a /deadpan look followed by, “You always cheer for the wrong side.”
2. Mother: “DEATH EATER! I ALWAYS KNEW IT!” (WTF, mom?!)
3. Dad: “If it makes you happy, be proud of it!”
4. Younger brother: “Dude, mom’s gonna kill you.”
5. Co-workers: Mostly random, incoherent squealing. Fangirls, I swear…
6. Some random little kid in line behind me: “MOM! There’s a DEATH EATER buying lunch!” (As a side note, the kid’s mother appeared absolutely mortified, and I was trying not to laugh.)
7. BFF of 20+ years: “You only got yours first because I couldn’t afford it that week!”
8. Grandma: With a smack upside the head, she echoed my wife’s sentiments, then laughed and said, “No cursing in my house.” That’s hardly a change though, the old German lady has never allowed cursing in her house.
9. Occasional random end users: “HA! You ended up having to work for Muggles! Sucks to be you!”
10. The tattoo artist (who, sadly, was not a Dark Lord of any sort): “I’ve done a few Deathly Hallows symbols before; this is the first time I’ve done one for the other side. Just remember, itching is NORMAL while it’s healing and not indicative of being summoned.”