I was looking for What Are Friends For by StopQuitDont. This fic was the inspiration for the premise of Faustian Bargain, incidentally. Buddy-sex, yum!

“Is he dead, Lois?”

“No! But I was really mad and I wanted to kick him between the legs and pull his nose off and put out his eyes with a freshly sharpened pencil and disembowel him with a dull letter opener and strangle him with his own intestines but I stopped myself just in time!”
- Further Down The Road by Terry Leatherwood.