They'll pay for it in the morning, honestly. When they're both exhausted and want nothing more than a little more sleep. But there isn't a hunt coming their way and even if there was, Sam wouldn't be the one behind the wheel immediately.

He keeps his tongue moving, pushing in slightly and pulling away, opening Castiel up little by little. One hand slips down, stroking Castiel's balls lightly but never all the way down to his shaft. But enough to keep his hand down there, to keep Castiel from pushing down against the covers.

Eventually, he pulls away, holding Castiel's ass open so that the air can waft over his hole. Then he moves away, picking something up and letting Castiel hear the sound of lube being opened so that Sam can slick his fingers. "Don't want to undo all my good work," he says, a smile obvious in his voice as he reaches down and slides two fingers straight into Castiel, the rimming having relaxed him more than enough for that.