O_O..........o_O........does......does she have three holes or am i just blind fucking retarded?!

Base +3, Sushilicious +28, salem6127 +2

I think that's a surgical scar - if she had any operations done on her tailbone, or if she was born with a vestigial tail (it's rare, but it happens) and it was removed.
Whatever it was, it was a pretty bad job that was done on it to scar that deeply.

Base +8