When I first learned what "slash" was, it was defined to me as "stories where you take at least 1 canonically straight character and make him or her gay." I was in the Buffy fandom though, so when Willow/Tara happened it threw things off. Is Willow/Tara slash? Willow used to be straight. Or just in general, the people who are squicked by slash are most likely squicked by all gay loving, so why not just label all same-sex couplings as slash and save us an argument?

I'm kind of a purist, and I still define slash as "at least one straight character going gay," but only to myself. Fandom at large seems to equate slash with same-sex.

(On a sort of related tangent, what do we call it when we turn canonically gay characters straight?)