Just a friendly reminder that while Castiel was punishing Meg’s behaviour (he explicitly says that he learned this from the Pizza Man, and his interpretation of the scene between the Pizza Man and the Baby Sitter had been that the former was punishing the wrongful behaviour of the latter).
Dean was doing this:
Dude is projecting himself in on the action with his whole body. He purses his lips. His hand makes a grabbing motion. But although Castiel has his back to Dean, Dean is paralleling Castiel, this isn’t even a little bit about Dean wanting to visit what Castiel is doing on Meg. Not Meg. They have history. Meg had just threatened him with sexualized violence. It’s not even a little bit about Meg, because Dean doesn’t see this as punishment like Castiel does.