I can't remember the title of this one, and I couldn't find it by looking through the Hustler-Justin tag. (Yes, I'm going to feel stupid when I'm told the title and that it was there.)
An AU, Brian and Justin haven't yet met. Brian goes out of town on business (Chicago? NYC?) and has told the potential client, a hotel owner, that he has a fiance. (Long story.) Brian's horny (of course) and rather than go out, he calls an escort service. Justin's the guy they send over. They're seen together, and now the potential client thinks Justin is Brian's fiance.
Justin's been working as an escort/hustling trying to earn enough to pay off a legal fine. (He got conned into forging some paintings.) When Brian hears his story, he wants to help. They end up getting married so Brian's money becomes community property and can be used to pay off the fine.
I can't remember if this one was ever finished.
Update: It's
For Richer or for Poorer by
galeandrandy. It's not finished, and the last update was in May 2011. Thank you to
itzy68 for finding it for me!