This should win an award for Truth in Advertising! Too funny.
I'm not a fan of tattoos, but I must say that I found this one quite appropriate.
And no, that isn't a slam on the girl. Not everyone's definition of "slut" is the same, it is a slang term and the meaning and implications of the term vary a lot. And it is probably context-sensitive as well.
Most guys would like their girls to be this slutty, at least once in a while in their bedroom.
Most of us probably also wish this particular girl were our slut, and could instantly begin reeling off a long list of things they'd like to do with and to her.