I know the title/description has something to do with talking dirty, and how Sam loves it when Dean does it. It's a short one-off, Sam is sucking Dean off, they can hear people outside the door, knowing someone could walk in at any time. When Dean finishes, he pushes Sam back and teases him through his pants and talks dirty until he cums in his pants and then makes him go back out into the party like that. I read it a few years ago . . .