Res ipsa loquitur

Well, you know, it doesn't even have to be first time, I think; I mean, any sex can be revelatory or transformative if you write it properly. I like reading down-and-dirty PWPs, but I reserve a special affection for the ones that are (and I think it was you, Res, who first put it this way for me) smut-and-more. When there's a story to be told inside the smut.