It's a super-sexy fanfic made by powerclaw1. It was the one story everyone wanted, and now PC1 is a god for making it a reality. Quote from a reviewer: "I came."
Read the sexiness here: https://www.fanfiction.net/s/10660936/1/The-Hawt-Smash-Fic-Everyone-on-GameFAQs-Wanted
And if you don't like it: http://objection.mrdictionary.net/go.php?n=7522128