FOUND: Wincest fic at a goth club (link in comments)

[anesthezea]

What I remember: Sam and Dean go undercover at a goth club or party. Dean talks to someone and Sam gets jealous. Sam pins Dean in a dark corner and sexy things happen. Prior to this, they had never done anything together, so Dean is kinda freaked out. Sam is very much in control of things, though. There was a sequel of what happened when they went

Comments

[tcs1121]

I think you're looking for the Phthonus Verse by Leonidaslion.

In fact, I'm pretty darn sure this is what you're looking for ;-)

[anesthezea]

Thank you!! That’s the series! :)