Here's a fic idea
Character of your choice having a private fantasy. Example, Gene imagines Sam as his informant/rent boy. Or maybe he'd rather go the other way and picture Sam as a Warren-like racketeer with Gene under his thumb. Same for Sam, he could be having little guilty thoughts of having DCI Hunt in his pocket. Or possibly scary hookerverse-like thoughts of submission. Could work for any character, slash or het. Oh, let me know if it's been done, I'd like to read it.
inspired by the er..up-against-the-fridge scene in "The Vice". No I haven't been wasting my weekend watching semi-porny TV