1. See "sexy" in a real dictionary.
2. "Sexy" for idiots that can't spell, or think that corrupting the English language makes them "mod" or "hip" or "alternative" or "crunk" or "swell" or "bitchin" or whatever the hell the kids are saying these days. This concept is also evidenced by the gradual substitution of "z" for "s" in plural noun forms.
"Words" like seksi corrupt the English language and make our children dumber by the generation because people are forgetting how to write properly.