Looking for a specific fic

[plumsuede.livejournal.com]

I am looking for a particular fic I read in someone's LJ probably two weeks ago by now. The fic made a reference to (I think) a signal (a slap on the Top's thigh) used by a bottom (in this case Justin) toward a top (Brian). The signal is used when Justin is on all fours. This scene actually happens in the show in toward the end of S3. I'm trying to find what fic I read that in. Thanx xoxoxo