The now-almost-hoary slang term for "disrespect" is dis, not "diss." Don't be confused by the doubled s in disses, dissed and dissing.
Occasionally you'll read about a contact "lense" or a camera "lense" because of similar confusion: The plural of lens is lenses. Another such confusion, however, has resulted in a legitimate word -- at least in English. Tamales, in Spanish, is the plural of tamal. English speakers, ignorant but hungry, saw all those tamales and invented the tamale.