Along this same vein is "The Bet" by Draccone. The guys bet Brian that he isn't capable of keeping a boyfriend. Brian, of course, takes them up on it and must establish and keep up a relationship with a guy of their choosing.

Here's the link:
http://www.midnightwhispers.ca/viewstory.php?sid=483

I hope someone can come up with what the orinal poster is looking for. I love "How To Lose a Guy in 10 Days" and think it would be a fun premise for a B/J fanfic.