LFSS where Blair wears a certain bandanna to a club

[finlaure]

Hi, I am looking for a story where Blair wears a certain color bandanna to a club and doesn't know what it means until Jim tells him and then they have sex,,, I think in the club. Then it turns out Blair had an idea what the placement of the bandanna meant and wanted Jim.
I know it is not much to go on, hoping that someone recognizes their own story even. Thanks in advance, finlaure