Some choice examples: "Avril Lavigne and Deryck Whibley's [wedding] reception": sexy. "Pam Anderson and Kid Rock's reception": skanky. "Hitting on a guy": sexy. "Hitting your assistant Naomi Campbell-style": skanky. Really, this stuff should be taught in schools. (And term papers could be graded as either sexy or skanky.)
Honestly, I'm so appreciative that Cosmo has clarified the moral/aesthetic universe for me. Although, already I long for even more guidance. Like, what happens when a sexy person and a skank have a child? (Is the child skanksy? Skexy?) Or what happens when two skanks --say, Christina Aguilera and Johnny Knoxville -- canoodle? Do they cancel each other out? And extrapolating from the Naomi Campbell example, is skankiness a misdemeanor or a felony?