Sam hasn't told Castiel not to actually speak. For now, letting himself talk is good for Castiel. And it doesn't stop Sam from smiling down at him. "It's meant to feel good, Cas. Though not too good. Not yet. Because I know it feels better when I push my dick into you, split you open on my cock. Know how much you like that." He pushes the fingers in just as deep as he can, one finger curling to try to find Castiel's prostate.