Initially, I was going to four-star this, because it's just a helluva lot of porn. If this were the porn equivalent of chocolate mousse, it would have kink instead of mousse and experimentation instead of chocolate.
Does that make sense? It doesn't make sense. Anyway, it's kinky porn, and Sherlock is experimenting with sex, trying to figure out how everything works - and especially how *John* works. And it's as delicious as chocolate mousse (I should stop going on about mousse, there's no dessert in the story).
"So," I said to myself, "it's hot, it works, the characters are in-character, it's fun, but there's not much else going for it. So it's, well - it should be more." But then, I wondered, "Why *should* it be more? It's hard enough finding good written porn as it is, especially in the D/s kink, with swinging on top, and this is just perfect as that."
I gave it a good, long thought, then decided I loved this as it was. So there we go. Good porn, although John and Sherlock take their time before they end up together. Go read it. Or not. Up to you.