[ What. A. Bastard. Crowley reads right between the lines, because Blake wants release, but he doesn't ever want this fantastic torture to end. It feels great, but he also knows it's doing him few favors. ]

Guess you're finally catchin' on.

[ Despite being in the form of punishment (of some variety) Blake had enjoyed leaving Crowley wanting and ready for more. It gave them both an edge that Blake can't deny has been helpful. ]

But I'm no pushover.

[ Which means he's wrapping a hand around Crowley's and forcing him to pump a little faster, a little more insistently. ]