hunting the internets for Good Omens fic

Specifically, one particular fic whose title and author I've forgotten. But not the highlights of the content. Aziraphale and Crowley, but not constantly explicitly on screen, with Crowley being inexplicably attractive to others will he nil he owing to side effects the relationship with Aziraphale. Culminating in a attempted sexual assault on Crowley by a 'colleague' that gets interrupted by Aziraphale getting his smite on. Which Crowley survives, owing to said side effects, and in the aftermath there's a faintly amusing mention of how he's now considered Aziraphale's by his 'colleagues' by right of combat, etc etc.

Funny how I can remember the plot, the highlights, the funny bits, but not who wrote it under what pen name and on what platform and where to find it. Argh.