Numb3rs Fanfic Finders

I'm looking for a specific story, but it's been a long time since I read it and my memory is rather fuzzy. Some of the details may be inaccurate or even wrong.

- It's an AU, Colby is still FBI agent, but Don (and maybe Charlie) are suspects in some case.
- People in the office know that Colby is gay, which is why he gets to go undercover looking for work from Don, who (they suspect) will find him attractive.
- Someone tells Colby something along the lines that if he doesn't/can't/won't do this undercover job he may as well leave the office.
- Don thinks that Colby is too perfect and intends to investigate his background.
- Don does think that Colby is attractive; I think he orders Colby to strip or something. Colby doesn't want to, but he does it anyway to get close to Don. 
- I'm pretty sure sex happens, but I don't know if it's an actual scene or just alluded to. Colby thinks the sex was great.
- Through all this, Charlie may or may not have been present.
- Pretty sure it's WIP.

I'd really appreciate any help you can give me!