Numb3rs Fanfic Finders

It's a fic I read a while back, but can't seem to find now.  The team were going to a Rocky Horror Picture Show, and were almost all in costume, and Don walks in, and somebody asks something along the line of "Are you a virgin, Agent Eppes?" or something like that because he had never been.  I do believe it was a Charlie/Colby fic, but i could be wrong.

Any and all help would be apppreciated.