Numb3rs Fanfic Finders

This may be a bit of a long shot but... Some time ago, I read a series of fics where Colby finds out about Don/Charlie. At first, he thought he was investigating to protect Don but finally he realized what he really wanted was to join them. In the last fic I read, Colby told Don that he knew he was sleeping with Charlie and that he wanted in. I don't know if there was more. Does it ring a bell for anybody?

Also, I'll appreciate recs for Don/Charlie/Colby stories or stories where someone finds out about Don/Charlie (with happy ending).

Many thanks in advance!

[Edit: It seem I mistagged the post but it doesn't lets me delete the "dom!charlie" tag. Sorry!]