I started reading this fic ages ago, and I can't remember a lot, but I remember that Dean gets bitten by werewolves, and then he gets possessed by Meg. I remember that Meg drives in a petrol station and starts flirting with the guy in the car/truck next to them, even though she's in Dean's body and Dean's still awake. There's implications between Dean and Cas by Meg, and Meg finds Cas and Sam and says that they can't exorcise her out of Dean, or else he'll be a werewolf. She's the only thing keeping him from turning.

I don't know why I stopped reading, but I lost it and I would like to read it again. Even if it's unfinished.
And it was definitely on fanfiction.net.

Any help finding this would be amazing!