As long as he didn't want Sam to put on a dog collar and crawl around on all fours they'd been fine. And boy was Sam ever glad they tightened the angel proofing because this was one moment of brotherly bonding he really didn't want Cas (or anyone) to see.
He let go of Dean's dick with an audible pop, lifting his head to look at him. "Planning on doing a running commentary all the way through? At least do something useful and grab the hand lotion from under your mattress... I know that's where you keep it."