WTF? 'Pulchritudo' is the 1st declension nominative form. 'Vitia' is second conjugation, present active imperative form and 'latet' is the third conjugation, present active indicative form. 'Vitia' means to spoil/corrupt.
So your phrase means: 'Beauty', 'I command you to corrupt' and 'lie hidden' 'inside'.
I've never studied Latin BTW.
OP: Tell your friend to learn a language before s/he gets some crap tattooed on them in that language.