Oh yeah - for sure there are definite parallels to slash and M/S, the most obvious being that for all intents and purposes - both a slash pairing and M/S had their most important, fundamental interactions within the subtext of the show. Looking back - it was probably this part of the relationship that I found so attractive, as I really do like to dig deeper when I am watching something - I like to extrapolate and make more. It's fun!