After legalizing unmarried sex, criminalizing pants

Boston.com: Va. bill sets fine for low-riding pants. Excellent. Glad to see that my home legislature is still taking care of the really important issues, like a citizen’s “intentionally wear[ing] and display[ing] his below-waist undergarments, intended to cover a person’s intimate parts, in a lewd or indecent manner.’”

This, of course, begs the question: what is the case law history that determines “lewd or indecent manner“ for underpants display in the Commonwealth? And how does one expose one’s below-waist undergarments in a non-lewd or indecent manner? Enquiring minds, etc.