In the Angel
ep Season 4 ep "Orpheus", at one point you can see Alyson Hannigan's tramp stamp. Which doesn't seem like the sort of thing Willow would have
Maybe she and Tara were feeling rebellious one day?
For the record I personally hate seeing those tatoo's on women. They look horrible to me. What's it even supposed to mean, a way of saying "Look at me, I take it up the arse"?