Hi, I'm looking for a specific first time, Dean/Cas PWP. I believe it's a part of a mini-series by the author; Sam and Gabriel are mentioned(Sam/Gabriel hinted at). It was a mini-series that alternated Dean/Cas and Sam/Gabriel.

Dean's driving down the highway in the Impala-something about picking Sam up at the library- and Castiel teleports in and gives Dean road head while he's driving. Dean thought he was going to crash the car until he manages to safely pull over. When they're all done, Castiel told Dean Gabriel told him to(or something along those lines).

It was really hot and I cannot for the life of me find it. Help!